Alright, i have both and I'll give a little rundown of each marker. The TiPX mags are light and relatively cheap, its a better gateway pistol because you could get more shots on your person before getting out of staging. It has a 7 round capacity, one less than the Tib, but that isn't that big a deal. The TiPX is significantly lighter, and to get more out of a 12 gram, upgrade your barrel. The TiPX IS lighter than the tib, this is due to its synthetic material/plastic counstruction, and plastic magazines. But, don't be fooled, the gun itself WILL hold up, but be careful with the magazines, a mis step could break them. It has a comfy grip, smaller than the Tiberius's because it does not have a twelvie in the grip.
The tiberius is beefier, some complain, but I like it. I like the trigger pull on it, its a nice stroke. The TiPX trigger pull feels lifeless to me. The Tiberius is also heavier, its mags are steel, have a tank in them, and the upper receiver is aluminum or some sort of metal. It is accurate out the box, and will really push the last bit of air out of cartridge. The mags FLY out of this puppy, with the help of some gas.
Both accept remote lines, but you need adapters. Any other questions, go ahead and PM me or ask in this thread. Welcome to Pistoling, mate.