There are basically five types of LowE coatings currently on the market. Three are "sputter" or softcoats and two are "pyrolytic" or hardcoats. Of the three softcoat products, basic LowE would be considered a high solar heat gain product. LowE2 would be considered a low solar heat gain product, and LowE3 would be considered an even lower solar heat gain product. Andersen's LoE4 has a standard LowE2 coating between the lites and argon gas for energy performance, but it also includes a titanium dioxide coating on the exterior of the window that makes the glass "self-cleaning". Although some folks might cringe at the term self-cleaning, the coating does work quite nicely and you will notice a difference in how they look and in how often you will have to clean the glass. Finally, the "4th" feature of the LoE4 is a plastic film that is applied to the glass in the factory that protects it from dirt and debris and even minor scratches during shipping and handling and install. Andersen's SunII glass is a tinted LowE2 that has very nice solar heat gain blocking ability and also it is nice because it cuts down on glare as well. Milgard's SunCoat is a standard LowE2 product - much the same as the LowE2 that Andersen offers as their standard. SunCoatMax is a LowE3 product. The LowE3 product is very new and has only been around for maybe 3 or 4 months - this doesn't mean avoid it because it is new - it means that it is an advancement of a proven technology and it works really well. LowE3 has the same heat blocking ability as a tinted LowE2 (such as SunII), but with visible light transmittance very similar to a standard LowE2 product - without tint. In the case of a west-facing door that has both heat and glare issues, then you may prefer a tinted LowE but with the understanding that the view thru the door will be less. SunII has either 38% or 40% visible light transmittance (I forget which version they use) and SunCoatMax has 66% visible light transmittance - again with very comparable solar heat blocking capability. Standard LowE2 (including SunCoat) has about a 70-72% visible light transmittance. Standard LowE has about a 78% visible light transmittance, but it also passes significant solar heat which is an advantage in places other than where you live. I didn't mention anything about hardcoat coatings because none of the products you mentioned use them. Also, they are much less appropriate in your environment (primarily cooling) than are sputter coats. No LowE coating has an affect on sound propagation thru the glass.

LoE-270 has a visible light transmission of 70%. LoE-366 has a visible light transmission of 66%. But with just a loss of 4% of visible light you gain: U Factor: LoE-270 is .37, LoE-366 is .24 Solar Heat Gain Coefficient (SHGC): LoE-270 is .37, LoE-366 is .27 All values are for the glass ONLY, the whole window will carry different values. Unless you are trying to gain more heat through passive solar heating in the winter, the 366 is a great choice. I did a simple 40"x78" casement and the upcharge was about $40. They also offer a LoE-340 glass. This is the "Turtle Glass" from coastal areas and significantly reduces the visible light (40%). I only use this as an alternative to tinted glass. "Turtle Glass" is required to prevent hatching turtle from going toward shore vs. the ocean. Make sure you don't get the wrong LoE-3! Excellent choice in window brand!

Nebraska isn't typically thought of as a climate that requires Low-e 366. That is typically for South of the Mason Dixon line. Triple pane is not an overkill option given the hot summers and definitively cold winters where you are. Standard Low-2 272 does a good bit of solar heat rejection.

Dew point is defined as saturation vapor density or 100% relative humidity. Dew point is the transition temperature between evaporation and condensation. Condensation occurs on windows because the temperature of the glass is below the dew point temperature of the air in the home resulting in moisture on the glass surface. There are two ways to lower relative humidity in a home – increase the air temperature or decrease the moisture content of the air. Lowering the relative humidity may solve the problem or it may have little to no effect – depending on how the RH is lowered. Increasing air temperature will lower relative humidity but it does nothing to affect the dew point temperature. Dew point is all about the amount of water vapor in the air and is not affected by air temperature. At any moisture level, higher temperature equals lower RH and lower temperature equals higher RH. Lowering RH by increasing air temperature may not affect condensation on window surfaces unless the rise in air temperature also results in a corresponding rise in glass temperature to a level above the dew point. Lowering RH by lowering the amount of water vapor or moisture in the air will lower the dew point. Once again, if the dew point temperature drops below the surface temperature of the glass it will affect condensation formation on the glass surface. Moisture level in the air is most easily expressed in grams per cubic meter (versus imperial version of fluid ounces per cubic foot). In addition, while this is nice for metric-speaking folks, it may be less so for non-metric folks. Since the metric version is much easier on the calculator than the English version, and in the interest of making this stuff easier to understand for all of us non-metric types, I am going to use grams per cubic meter, but also Fahrenheit rather than Celsius for a couple of quick example calculations. Consider two virtually identical homes located right next door to one another. In this scenario, home number 1 has an internal relative humidity reading of 40% at 65°F, and home number 2 has an internal relative humidity reading of 29% at 75°F. Both homes have 6.25 g/m³ moisture in the air inside the home, irrespective of the RH differences between the homes. Because they have the same moisture level, the dew point in both homes is 38°F. At dew point, or 38°F, relative humidity is at 100%. Above this temperature, moisture evaporates, and below this temperature, moisture condenses. While the relative humidity in the second home is much lower than is the relative humidity in the first; if the surface temperature of the glass in either home is 38° or lower those windows are likely to have surface condensation regardless of the substantially lower RH reading in the second home. If glass surface temperature of the windows is 40° – only a couple of degrees warmer condensation becomes much less likely. If glass temperature is below 32°F then that moisture is going to form frost or ice on the surface of the window. In order to stop condensation from forming on the surface of a window you have to: (a) lower the dew point temperature of the air to a level below the temperature of the window surface, or (b) you have to warm up the window surface to a temperature above the dew point temperature of the air, or (c) a combination of both. I am not a huge fan of casement windows for a couple of reasons, but primarily it’s because the glass surface sits well proud of the house exterior wall when installed. The best way to avoid window condensation is warm glass, and the best way to avoid warm glass is to hang the glass package a couple of inches past the exterior wall when it’s really cold outside. You have to either warm the glass somehow or else you have to lower the moisture level in your home. Judging by the amount of ice that you have on those windows, that glass is cold, really cold and warming the glass is probably your better option. Looking at the picture of the window next to the popcorn machine, it might take a small fan or even a small portable space heater near the window to give it that extra warmth on the extra cold days to avoid condensation and ice build-up.