Hi T.C. ( and welcome to the forum ). :)
I have a 335 copy, in which I have tried Alnico II Stormy Mondays, Alnico IV Stormy Mondays and 'stock' ( i.e. Alnico V bridge / Alnico IV neck ) Mississipi Queens.
My favourites have remained the Mississipi Queens. Stormy Mondays are lovely pickups, but the bass end was never quite tight or loud enough in a guitar of that nature. The Mississipi Queens sound lovely and rich , fat , clear on the top three (unwound strings ) - but defined and assertive ( without being harsh ) in the lower registers.
My summary was:
Alnico II Stormys = sweet top end, but slightly 'blurred' bass response.
Alnico IV Stormys = Bass became clearer, but the top became a bit brighter and harder.
Mississipi Queens = Best of both worlds, giving B.B.King / Larry Carlton tones on the top strings, clear sweet bass and a real hot push that gives a lovely thick but clear and expressive clean tone - and could tastefully overdrive the amp without too much effort. For me, these where the real 'discovery' amongst the pickups I tried. I would never have thought I would be ordering P91/P92 style pickups ! One 'secret' for me is getting those pickups closer to the strings, with strings fretted at the last fret, pole pieces on mine are 1/16" from the string. Many settings work though, but it sounds thicker and more 'Lucielle like' to me at that setting.
Of course my results could be because of the woods used in my guitar, but Tim ( after putting Alnico IV magnets in my previously Alnico II Stormys ) suggested that the next 'vintage' options would probably have to be Riff Raffs or M.Q.s
Knowing my preference for mellow, he and forum member 'Twinfan' recommended the M.Q.s - which are now my favourite pickup for the semi-acoustic.
Fear not though, for all the pickups in that 'zone' ( i.e. Stormy II and IV , Mules, M.Qs ) sound lovely - so there is no 'wrong ' choice, only degrees of being appropriate to your style. :D
