You are right. The smaller the window the less problems. Be sure to lock your window every time you close it. This helps to keep the sash and hardware matched up. I believe Marvin has a pivot pin on the hindge to make small adjustments. Have you considered an awning unit, opens from the bottem. You lose some ventilation, no site lines and less $$$$.

+1 to roof35's comments. Sounds like a botched install. Plumb and level are of little consequence (within reason of course), the main concern is that its square. Your installer should have put his level away and adjusted the window based on the sash to frame reveals which would have alleviated this. Regarding the hardware, Marvin uses the same (or similar) hardware as any other window company. I can see why you might think that is looks insufficient, however it is all engineered with maximum capacities based on size, weight, etc. Reputable manufacturers like Marvin are very conservative in staying well within those parameters for long term performance. It sounds like you are now stuck in the unfortunate situation where you sourced the windows and hired a guy to install them. This situation results in failure at a very high rate and inevitably ends in finger pointing. Your best bet at this point is to get the installer and a manufacturer or supplier rep there at the same time to hash things out and come up with a gameplan to address.

How old are the units again? I realize that you do not want to replace all of them, but more often than not, the condition of one is indicative of the condition (or impending condition) of the rest. In this case, it is not like this unit was behind a tree, bush, or subjected to any more weather or moisture than was likely experienced by the other units. Might be time for a careful inspection of the remaining units and look at the project, unfortunately, in more totality. This is not the rule, just an observation. Hopefully the other units are just fine at the end of the day.

I have been in the market for windows for the last year or so looking over my options and pretty much narrowed it down to the Marvin Integrity All-Ultrex and the Andersen 100series. I currently have aluminum clad wood casement windows which are original from 1986, and are replacing with casements. I have total of 12 windows (5 of which are mulled, and 7 singles) as well as a sliding patio door. All of our current windows have rotting wood, some sashes under the aluminum clad totally or partially gone, paint faded off the aluminum, gaskets between aluminum and glass are shot and a lot of hardware failure, mainly do to rotted wood. We live in Southwest Pennsylvania so we see cold winters, hot summers and your typical day/night temperature swings. We are looking for a casement window that's easy to clean, low maintenance, must have a white interior and a contemporary look. We have pretty much narrowed it down to the Andersen 100 series and the Marvin All-ultrex, both of these fit what we are looking for. We are trying to steer away from clad wood for those reasons stated from before and the fact we want a white interior and we don't like the look of the pure vinyl. I was pretty much sold on the Integrity All-Ultrex, however with the lack of a custom sized sliding patio door started to make me look else where, and I was not completely fond of the somewhat flimsy widow stops, but it could be over looked. So I happened to come across the Andersen 100 series Fibrex which look very similar and in some respects look better as well and looking at the architectural details look sturdy and well built, only questionable is the piece that holds the glass on the exterior side, where as it's a one piece on the Marvin. 100 series Ultrex Performance number are pretty close to the same for both as well. The glass package to my knowledge is the same Cardinal glass and in both cases looking at the Low E 272. In either case we would be finishing off the interior trim in a composite material as well. I guess I am just looking for some feedback on these two windows, if anyone has considered the two, also in terms of durability, performance, longevity, overall fit and finish and how happy you are with the windows. As well as what made you decide on the window. Lastly if any installers have feedback on these as I will be installing these myself with a nailing fin as I am replacing my siding at the same time. Thank you!