FAL
I think the Saiga is a good rifle, but the FAL is the better one.
1. Reliability: It's a wash. The AK's reliability is legendary, but the FAL's is not far behind. Add in the fact that the AK's legendary durability is based upon experiences with the weapon in 7.62x39, and this is a rifle in a completely different caliber, with different specs and different forces...eh, I'm not sure the comparison is valid.
2. Sights. It's a rare situation where you can say that the FAL iron sight system is superior, but this is one of those times.
3. Optics. FAL + DSA mount = rock solid optics platform. Saigas suffer from the issues present in all AKs with mounting optics. They're able to be overcome, but not as readily as the FAL.
4. Parts availability: If something in the FAL breaks, you can get spare part very easily, from a number of sources. If something in the Saiga breaks, how common are spares?
5. DSA has a lifetime warranty. Saiga does not.
6. Ergonomics. Entirely subjective, but I like the FAL's better.
7. Accuracy. Probably a wash, but the DSA can be plenty accurate. Not sure about the Saiga. I imagine that individual differences between rifles would be larger than the differences between designs, but that's a guess.
Mike