Mak 90s, and perhaps other AK clones may show better workmanship (I've never made a detailed comparison), but I have two SAR-1s and am very happy with them. I think the SAR-1 is preferable to the SAR-2 and SAR-3 because the 7.62x39 is more readily available and cheap, and I don't see much reason to go with a small, high-velocity caliber on a rifle that isn't full auto, and isn't especially accurate for long-range shooting. A couple of significant advantages of the SARs over the Mak 90s and many other AK clones is that the SARs come with a pistol grip, and enough US parts to make it legal to use imported AK magazines. I think that if you want to do this with most other AKs, you would have to buy and install several more US parts (or live with the thumbhole stock, etc.). Also, the SARs come with the AK receiver scope mount installed - that makes it a snap to install any of the AK-style scopes or red dot sights, and it it is more solid and "authentic." I have a Russian Military-style Cobra red-dot sight that mounts on my SARs easily. I also added black plastic Bulgarian-style stocks to one of mine. It looks very nice, is legal, and works very reliably (as does my other SAR-1). I think $350 for one of these is a good price - you'd have to work pretty hard to beat it, and if you could it wouldn't be by much. I ordered mine for $320 each a couple of years ago - but by the time I added shipping and FFL fee, it comes out to more than $350.
Doug