If you want to tinker on the weapon, doing your own gunsmithing which is well within amateur levels, the Saiga 12 is the way to go. For me, it was fun actually doing even a small amount of work to adjust the weapon to personal tastes. Since having it assembled, I have had more fun with the Saiga 12 than any other weapon in my arsenal. It always gets looks at the range and is the envy of many of my friends. My vote is for the Saiga 12, but only if you are interested in doing the work yourself.
If you want something that is pretty decent and neat looking out of the box, go with the PSL. It's unique looking and fun, but not as accurate as many other, more conventional rifles.
Both have their advantages, I just prefer the Saiga 12.