Well, it depends on your luck at purchase time. Many have bought the rebuilt FALs and have had no problems at all, while others have had many problems from day one. If you buy one of the cheaper Century built FALs out there, you might end up spending just as much money fixing the problems as you saved buy not buying a DSA.
Bolt hold open pins have been removed, gas pistons have broken or been too warped to function, fire control parts made in the US have been known to function improperly or not at all. It really is a crap shoot buying a rebuilt FAL when any part on it is marked CENTURY.
Let me just add that I don't own a DSA but have bought many parts from them and seen/held thier line or FALS. Price was an issue with me so I built my own, but man if I had the money I'd have a room full of DSA FALs
Frankly, it's much easier to build your own as you'll know what you are getting and what kind of quality went into the build.
DSA produces some of the best FALs out there, but you need to remember, while some of the rifle parts are made in the US, some are from demilled kits. While I have no problem with DSA quailty, function or appearence, I do have a problem with the price. That is the ONLY problem with any DSA rifle I can mention or think of. You can't go wrong buying DSA if you have the cash, but even they have answered the price issue by making an STG58A Authentic Austrian FAL with a lower price than some of thier other FALs. I would buy any FAL DSA put on the market as I know it's going to be a quality item, however I might be more inclined to pick up the newer STG58A Authentic Austrian FAL than a higher priced item.
There is a newer rebuilt FAL on the market which has been getting good reviews called the
Israeli Arms International M444 FAL rifle. I'd also buy one of these or a DSA before I bought anything else.
Good Luck
Ted III