More layers of glass + More Low-e = Lesser VT.

If you are going to have an efficient, triple pane window, it is going to be a bit darker. Such are the trade offs.

+2 on WOW’s comment. I have triple panes and don’t notice the lower VT numbers, but some are mch more sensitive. you should contact Homesealed , he sells Okna in Wisconsin and can walk you through glass questions.

+3

what they said

I will concur on the all of the above.

I narrowed it down to these two windows:

Polaris ThermaWeld + (these are about $5400 for 5 installed) vs. Okna 500 ($5500 installed).

Polaris: https://polariswindows.com/twindows.html

U .27, SHG .22, LVT: .48, CR 59

Air leakage: .02

Okna: https://www.oknawindows.com/product/double-hung-insul-tec/

U .25, SHG .29, LVT: .53, CR 63.

Air leakage: .3

Both companies that install them have been around many years and provide additional coverage including glass breakage, no labor, etc.

Okna 500 air leakage is .02.

The difference in visual transmittance and Solar gain numbers are due to the different types of Low-E coating selected .

Data on the Okna is better in that comparison. Not reason to not go with that option unless you want to bump up the performance and look at triple pane.

The cost to install 5 Okna 500 DX windows is $5330. Is that reasonable? This site seems to be way under priced in concern to actual item and install cost.

"This site seems to be way under priced in concern to actual item and install cost."

Impossible for people to 100% gauge your end price without actually being to your home. The pros who post here as also located all over the country and pricing is very regional, both labor and materials. All anyone here can give is a best guess realistically.