I've got the Bersa Thunder 45 UC Pro in the matte black finish which I purchased in 2010. It's a good gun for the price and mine has been reliable and very accurate for me. The DA trigger pull is long but fairly smooth on mine, and the SA pull has a little travel but is still good.
Size-wise, it's just a little bigger than my Glock 26, and a little heavier, bit it is all metal (alloy frame) with the only plastic being the grips. It's not really what I'd consider a concealment gun per se, due to the double-stack magazine, but in a good holster (I use the UBGHolsters.com "Striker" IWB model) it carries comfortably under a cover garment of some sort.
For some reason the shape of the grip isn't perfect for me, so that when I point naturally the barrel is aimed downwards somewhat, while my Glocks point dead on. I guess I'm one of those weird people for whom the Glock grip-angle was engineered. It's not that big of a deal, and I can easily adjust for it when shooting, but if natural pointing is important to you I'd definitely handle them prior to buying.
There have been some issues with mottled or splotchy finishes on the matte black slides (mine is like that) so if you want a prettier finish, you might consider the two-tone which has a nickel slide. However, for a concealment gun I don't find that it matters much.
I shot it fairly often when I first bought it and never had any problems with it. I've fed it UMC, Winchester white box, and several hollowpoint SD rounds with no hiccups. I haven't given it much range time recently because of the cost of .45 ammo compared to 9mm.
The recent models have replaceable sights that are compatible with Sig P226 sights, in case you want to customize them. You're pretty much stuck with the grips, though there is a guy in Europe who makes some beautiful wooden grips for them if you really want to dress it up, marschalgrips.com is the place.
It has very good ambidextrous controls for the safety/decocker and slide release, and I believe the mag release can be swapped to the other side if you want.
There's a whole forum for Bersa enthusiasts (Bersachat.com) that might be a good source of more info for you.