When I used to spin fish for smallmouth I found that nothing beat a gitzit (tube lure on a lead head jig). I will admit that at dusk I always went to a topwater bait though - and did well. Based on these memories I plan on fishing some bottom pattern when I pursue smallmouth this summer. The 350 grain is not just for saltwater situations! Granted - fishing for smallies on a 9 wt rod is not great fun but it is a decent experiment. I have a 250 grain line and I did cast that on my 5 wt this past summer. It was not delicate but the rod did not feel like it was going to snap as long as I shot as much line as possible after the back cast. I have a cheap 7 wt rod and the 250 grain will work well with that setup.
I have done well using clousers for smallmouth. I regret to inform you that I did pretty well with deep eels last summer too. All bass love the the Deep Eel.