With Alex Smith probably done as a starter, it's worth considering him as the stereotypical "pretty good" QB. Every team that has him wants to upgrade, but there's always been another team that considers Smith the meaningful upgrade.
He helped 3 teams (SF, KC, WFT) to overachieve and improve, but was never one of the top QBs in the NFL at any point.
14 seasons, 3x Pro-Bowler, #215 all-time by Career Weighted AV, 35k pass yards (#27 all-time), 63% completion rate - basically the definition of solid, not great.