General comments are possible but the "better" question cannot be answered with just the information provided. With the caveat that metallurgy isn't my field: 300 series corrosion resistant steels (CRES) include nickel and chromium with the iron and are non-magnetic. They may take a better surface finish as seen on stainless flatware. 400 series CRES do not have nickel. They are more corrosion resistant under some conditions, not normally applicable to a kitchen hood. They may allow better (less brittle) welds. They are magnetic. Color may differ due to the nickel, which by itself is yellower than chromium due to lower reflectivity in the blue end of the spectrum. My Wolf branded, made by Independent, Pro Island hood is non magnetic and presumably a 300 series stainless steel. Welds look good to me, but the cost was high enough to pay for quality work. I have a decades old magnetic Revere Ware pan that works on my induction cooktop. It is presumably made with a 400 series steel. The steel is less shiny inside than similarly old Farber Ware pans that are non-magnetic, presumably 300 series stainless, and not usable with induction. (Note that stainless steels are not truly stainless, just stain resistant. I had to use phosphoric acid to clean the hood extension of factory supplied fingerprints. Brushed stainless is harder to clean with polishes than smooth stainless.) kas

We just installed a Zephyr island hood last week & love it. It is 42" over a 36" gas cooktop. Workmanship is great, the stainless is beautiful. The pull is great (720 cfms) & quiet in mid to low range, but hear air pulling in upper speeds. (This replaces a 2 speed JennAir Downdraft. There is no comparison.) We purchased on-line for $1600 to $1700, but am thinking under cabinet should be less. I don't have experience with the other hoods.

Broan E64E30SS with Broan's 600 CFM or higher remote or in-line blower will do the trick. These utilize 10 inch round ductwork. Remote blowers install on the outside of your house, either on the roof or an exterior wall. The In-line blower would be intalled in an attic if you have the room. These tend to be slightly quieter than the remote blowers. The higher the CFM output a blower has, the quieter its operation on low setting, the most common setting. also look at Vent-A-Hood 30 inch 600 CFM units. These are a bit quieter for normal and high settings than the Broan but work best when the output from the hood is vertical, not horizontal. Also, if these appeal to you, have a saleperson show you how to dismantle to clean. It's not hard but it's also not for everyone

I chose a VAH simply because my cabinet company uses them as liners for their hoods. (I also did research here and people seem to like them.) I can't say from a lot of experience because I am just starting to use it, but from having a small, extremely noisy and useless recirculation hood before, this has been a DREAM. I don't set off the fire alarm when grilling burgers anymore! It is SO quiet compared to the old one, but I don't think it's the quietest. From being on the boards for a while, you are looking in the right direction, VAH and Best are popular here. Zephyr has nice looks too. I don't think you will go wrong with any, just make sure you like the controls/cleaning method/looks and choose that way. (I have not cleaned mine yet). If you are going from nothing, it will change your life! (steaks, fish!, wok, saute... no residual smell!!!)