Both are nice, but be wary of the CETME. Spain has a bad rap for steel quality. I almost bought one of thier Guardia mausers, but after reading the posts on the C&R forums, I declined. For a bit more money, you might check out the HK 91 clones. Same look as the CETME, but usually better built. All 3 can be a crapshoot, just depends on the original kit and the builder. I got lucky with a Centurion 91 built by Century Arms. It was built from a kit of 1962 HK parts and shoots like a dream. Check places line Aim Surplus, J&G Sales, Southern Ohio Gun, and Century Intl. Arms. I've put about 1500 rounds thru my '91 and love. I keep 20 mags fully loaded at all times so I can quickly drag it to the range and blast away for hours.
The cleaninig point is dead on. And you have to be sure to clean really well after firing. Not sure about the FAL, but the CETME and HK styles use a fluted chamber to allow the gas to cycle the bolt. Because of that, you have to make sure you use good ammo. I bought some Venesualen .308 and in less than 50 rounds, it was so fouled I had to stop and clean the chamber. India made .308 is nearly as bad. THere is a lot of Australian and Spanish ammo at the surplus houses thats shoots nice and clean.
Any of the 3 are nice, best if you can see it before you buy it...