The MBA 15" is a win. I'm definitely going to sell my 14" and get one eventually.
It took Apple two decades to finally realize that there is a market for people who want a bigger screen but don't need extra performance. This solves a huge gap in the Mac lineup, IMO. For as long as I can remember, I never understood why I was forced to buy a $2000 MBP with Pro performance just to get a big screen when in the Windows-PC world there are tons of low-cost 15" and 17" laptops for those that just want a bigger screen.
I originally had a 16" M1 Pro and while it was an incredible laptop, it was a brick and I barely used it. I then downgraded to a 14", which I use a lot more, but I miss the big screen. The MBA 15" is what I've been waiting for.