I was searching for some info on the Internet and found this topic. I see you're (or were) a worried user of the mentioned bike so I felt the need to share my experiences with that same model.

First of all, it's NOT a Walmart Schwinn! This model is a Select Series, produced when Schwinn was still a decent brand and I bought it for about $800 when it came out in 2004. It had pretty crappy components on it though. However, the frame is indeed very worthy of upgrades (if you don't mind some outdated standards). It's a very sturdy frame, low, slack and stable and because of that I've upgraded it with better components.

I'm still riding it hard and, in-fact, racing on it. When not racing, I take it to the local mountains (Zagreb, Croatia) and it handles 6000 ft elevation rides with bumpy, rocky and rooty terrain with occasional 3ft jumps with no problems.

I guarantee that if you swap some parts it can be a great bike to ride.
Mine is a 1x10 now with SLX/Zee/RaceFace components, XT disc brakes, a dropper post and so on. The first thing I changed on in was going to a 50mm stem and 720mm bars and installing an air shock. Made a huge difference as the stock stem/bar combo made it ride like a boat and the original shock was too soft. The Suntour fork is also utter crap but won't fail easily. Mine's rocking a proper RockShox air fork now. Would love to post some pics of the upgraded bike but I'm still a newb to this forum

Also, if you're still planning to service this bike, I would advise a change of rear-linkage bearings. It uses six 608 2RS bearings which are extremely cheap to replace and the linkage should work like a charm after the replacement.

Ride that bike! It won't let you down.