I'll have to try it again to make sure I remember right, but a few years back I mixed (I think) a 910 and a 469. Ended up with a 910SSV, and the most nose-heavy 469 you'd ever want to try and get on target. I seem to remember one of them cycled fine but the other had issues, and I don't remember now which was which. I do know I put them back the way they came from S&W. Oh well, now you've given me a little something to do over the weekend.

Edit: Decided I had time just now to try it again. The 469 slide went on the 910 great - seems to work fine. However, the reverse was not true. The 910 slide wouldn't go on the 469. Oh well.