I was going to go with them, but a little digging has turned up weirdness.
Some people say they have a lot of BBB complaints, but the number they cite is more than is listed on the BBB site. The BBB gives them an A+ rating, but it's claimed that's only because when customers sic the BBB on them, they suddenly become very responsive to complaints.
It's also said that Appleby's windows are made by Jantek, and available much cheaper buying direct from them... but I also see sites (which may be owned by Appleby) claiming that Appleby is Jantek's own contracting/installation company.
It's all confusing to someone who really doesn't know all that much about windows or contractors. Before I drop $5K on replacement windows (that's for making and installing five custom sized windows - our old house has windows about 3x6')
Nothing in this post represents the views of my current or previous employers.
"Isn't that just like an elf? Brings a spell to a gun fight."
"Sci-Fi writers don't invent the future, they market it." - Henry Cobb
If yes, then invest the extra money and buy the best. The price per year will be minimal and you'll be glad that you did 10 years from now. I'll echo Pella and Andersen.
"Always do what is right. It will gratify half of mankind and astound the other."
I'm about to put in new putty on some windows in my house. Only two old style pane windows, though. In the room with the wood stove, so it's nice if they'd be even more drafty.
I have a couple Andersons, but some Peachtree where the seals on just about every one is shot. Don't cheap out unless you don't plan on staying, as Nebu said. It sucks to have crappy windows, but I'm of the mind that it's always worth getting the best thing you can afford in any category. Life's too short to live with cheap shit breaking down.
You can order custom sizes from a major manufacturer like pella and 3x6 doesn't sound like that odd of a size to me. I personally think 'the local guy that builds you custom windowas for 500 a pop' is a total rip off. I am in the process of replacing 8 windows in my house with vinyl/low e/argon filled pella's (5 down 3 to go) and they are pretty nice. 3x5s ran $220ish, 4x5 was $300ish, and the 6x5 was $500ish. Saving about $100 a window by installing myself.