Kisara, the SPR grip is great for a match gun, but is wearing thin as a "practical" grip. Ambi capabilities suck with the SPR, so I'm looking at a few other grips. A few guys that I shoot with use Ergo and the TangoDown grips, and I've found that they work a bit better when i shoot lefty. Don't get me wrong, cause my big paws (I wear a size 11 glove) love the grip, I just hate not having the ambi capability.
As far as choosing the #50... Well, when I bought it, the #50 was the only slimline on the market. I was using a Surefire M962 on the FFRAS that it was going to replace, and I knew that my light would be unusable unless I bought an SU tapeswitch or got the #50 instead of another #45M. So, I bought a #50, tossed the FFRAS in the parts bin, and was a happy camper for the time being. I eventually bought an SU tapeswitch, moved the M962 to the other SIR upper, and used one of the spare M3s on this one.
Sorry to be so longwinded about that, but I figured there was no use in making a long story short ;-)
Thanks for the compliment, btw!
-Cap'n