The Mini-14 is an well made rifle. I would take one any day over either the SKS or the Saiga.
I've never been a fan of the SKS - owned a chinese one and didn't like the way it functioned, the way it felt, or the way it looked. I know that since the import ban that they aren't as common, but they are a down and dirty cheap rifle, in my opinion.
I have shot a mini-14 and own an AC556 (basically a full-auto Mini-14). Accuracy is not a real issue, since I have the 13" barrel on it.
However, the rifle is not inherently inacurate. ASI can put a custom barrel on it and turn it into a tack driver. The weak point in the Mini-14's as far as accuracy is simply the barrel. One thing I don't like about the Mini-14 is that Ruger doesn't make the parts readily available. Also, I never could figure out why Ruger didn't simply make the Mini-14 to use AR15 magazines. In semi-auto, you can pretty much use any decent after market mag. In full-auto, the rifle is a bit choosier.
The Mini-14 barrel, althout not made to be a tack driver, is NOT prone to wearing out - they are very tough and durable. I have shot my ac556 in full-auto until the thing was too hot to hold, and never came close to damaging the barrel. In fact, I've often thought about putting a heavier ASI barrel on it, but simply can't justify it because the stock barrel is tough as nails.
If I could only have one .223 rifle, I would probably choose a modified Mini-14 over an AR-15 for the following reasons:
1. I the way the Mini-14 looks in a tactical wooden stock, or even the SCAR stock.
2. It's all steel.
3. I'd get the all stainless - preferably the older style that was a bit brighter than the new dull stainless (purely cosmetic preference)
4. I woud upgrade the gas block and put an ASI heavy barrel on it with a compensator.
Now, I might have $1700 invested in this thing when all's said and done, but It would be a real tack-driving beauty compared to a Beer-Can 15.