I have a Tiberius T9.1 - the hand grip is massive and the overall pistol is larger than a Spyder MR1. That being said, it's a cracking piece of kit. The old Splatmasters are a hoot to use, but you have to recock after every shot.
Ask your friends if you can play a game/s with their TipX's (just the TipX only) and see how you get on with it. They have a good reputation for a reason
If it's just a back up then I use an Umarex t4e HDR 50. It's a 6 shot revolver but pretty easy to reload. Just over £100 and it comes with 5 six shot cylinders.
Mate, I totally geeked out when I first got mine. Got hooked on the whole 50cal scene, stopped looking at porn and got caught searching for pics of custom revolvers and cosplay weaponry...