While I think wins/losses are a limited way to "evaluate" any player, it is worth noting that Kap's last season was 1-10, is 2nd to last season was 2-6 and nearly half of his 28 wins (compared to 30 losses) were in a single season. Thus, he is not a good example of a bad QB with a good w/l record... just like The Golden Calf of Bristol wasn't... I also never thought Kap was as bad as some did. The wheels really came off that SF team and I found it hard to blame him personally.
I'm highly uncertain about his ability to stay healthy.
Getting healthy is one thing. He'll have time to do that. But after a couple of years now of shoulder problems, foot problems and other problems, it's pretty tough not to characterize throwing significant money his way as a gamble.