Correct animations, reasonable amount of polys, the scope is well aligned, two extra textures (black and nickel with flames) makes this a good HD version for TS. It's a whopping improvement over the original model.
About the cons, the red rubber cushion on the grip is missing (not a big deal) and the bullets are clipping through the cylinder flutes (noticeable on W model). However its main problem is its scaling. Compare how it's ingame and how it looks massive in real life.
The model looks too small compared to the hands. Just scale it up like HL2 Python or a bit smaller and it will be perfect.