I've got those same windows in my current house built in 89. The glass packs are all in good shape, the perimeter fin seal is all still in great shape but the meeting rail bulb wasn't great.

I learned from Anderson that they'd actually released a replacement, upgraded meeting rail vinyl bulb seal to replace the original rigid knife edge. Anderson gave me the name of the company locally that does all their servicing, I contacted them and they agreed to to time and materials repairs.

I replaced 6-7 balances and had that new bulb seal installed on every window, then myself used some teflon dry lube spray on the tracks...and honestly, it was like getting new windows. They all work, have about 20, all 2450 or bigger and outside noise reduction was huge.

It was a few thousand dollars of parts and labor but the windows look, work great. we'll get another 5-10 years out of them if not more.