John, I have a Bushnell Legend 5-15x40 on my FX Cyclone. Great scope! Clear, sharp optics, excellent light transmission, clicks are solid, audible/tactile, and accurate. Mine has a mil dot reticle, I think that's only available on the 5-15. AO is good down to about 7 yards. I think these may be one of the best bangs for the buck in the under $200 price range. The only question mark would be springer use, I don't know if they'd handle the pounding. I believe I read somewhere that ALL Bushnells are springer rated, but I'm not sure if that's true. I do know the Legend is popular among FT shooters on a budget, especially HFT. Sorry, that's Field Target and Hunter Field Target competition, if you're not familiar with the terms. The only "issue" I have would be a small amount of fish eye effect at higher mags, typical of wide angle lenses. Not a complaint, it's really not a problem, just noticeable so I figured I'd mention it. Length and weight are comparable to the two you mentioned. I'd go for the 4-12, I always felt that was a perfect power range for a springer. If you like/prefer mil dots, I think the 5-15 is you only option. Hope that helps, and good luck.
Dave