If you find one in good shape, and you don't have to carry it, it's a decent system (or it was 15 years ago when I was still using it). The trick is to find one that hasn't been abused, stored improperly, etc.
Its a good system, but built for durability/longevity over weight and packability. Its painful to carry all the components but if you dont need the full kit you can shed a few pounds.
For $100 you can/could get something like a Kelty Galactic. I use one and for a budget bag, its pretty damn good. Its not gonna keep you comfortable at the temp rating, but add 5 degrees and it will be ok. The treated down helps stay warm when damp. Ill be looking to replace mine with a 0 degree bag, but for the price point its pretty solid and packs down much better than my USGI one.
These guys as spot on, as former infantry Devildog I can tell you to chuck the bags and buy a new one, keep the goretex bivy if a gen 2 as they are not bad weight wise and are tougher than commercial ones.