Personally, I think anyone can do very well with ALMOST any gun if they have a good setup for themselves. My uncle has an auto-loading 12 gauge, and after only putting about 10 rounds through my own Mossberg 500 pump I was shooting just about as fast as he was. Obviously, you're going to have more movement with your arm with a pump, but if you spend enough time (and money on ammo) you'll be able to get perfectly used to your gun. On the note of "having a good setup for yourself," there are many options you can pursue (especially with a more modern gun). Stock replacement, different barrels, opportunities to find a type of ammo that you like (Remington, Federal, Winchester, Brenekke, just to name a few) can all effect your gun's balance, performance, and your skill with that specific gun.
Now, if you get this gun that you're looking for with synthetic accents, it's gonna cost less (like you said) and may also weigh less than that gun's equivalent with wooden accents. If you like that gun that you rented and you do very well with it, go right on ahead and buy that same gun with the same setup. If your preference ain't broke, don't fix it...