No offense, but it sounds like you were against the pistol from the start. Manufacturers don't always get the proper information about "problems" from the field and I, for one, if it was my business, I'd be really sure a recall was needed before I started one. I sympathize with you on your problem, but it sounds like Smith was willing to send you a new slide stop. What else can they do? Have you send in the pistol to replace the slide stop? Also, I don't blame them that they wouldn't remove the magazine disconnect. I can only imagine what the liability and bad press would be should, heaven forbid, someone was injured or killed because the magazine disconnect did not work. As far as the 340 goes, take it to a good gunsmith and have him do the work.
I've had Smith Autos over the years, and although I never liked the 6906 series, as a duty weapon, I put 12,000 round through one and 14,000 rounds through another and I never had a malfunction that wasn't ammo-related. I've also owned a 5906, a 39-2, a 469, 539, and I'm not sure what else, but they have all functioned and performed well. Maybe I'm just lucky.
Sorry if this ticks you off, but Smith & Wesson is still an American company making American-made products and I think they are trying hard to satisfy their customers.
Steve