I've got an Arsenal SGL-21 and a Ruger Mini-14 586. Honestly, for a dependable gun, I'd have to go with my Mini-14, but thats just because of how I have it outfitted. I think the most important thing for you to consider is how do you want to equip your rifle? Irons, red dot, or scope? Rails/Pistol grip or a simple traditional stock? How far do you want to be able to shoot?
My Mini 14 feels like 8 lbs and looks like a 5.56 M14 with an Accu-Strut, m14-style flash hider, choate vented handguard, Nikon 3-9x scope, and sling. It's much more consistent than my AK (With the strut and 55 grain V-Max reloads I've gotten 10 shot groups around 1.5-2"). The Minis aren't so accurate out of the box, but theres stuff you can do to them to fix that. I like the feel of the rifle better than my dad's AR, or even my AK. Its lighter, more comfortable, lower profile, and easier to shoot. YMMV.
My SGL-21 AK weighs...probably close to 10lbs with a Leatherwood CMR (Good scope, but heavy), Midwest AKSM mount, and a crappy paracord sling I made. It shoots OK, but the round is pretty much limited to 300 yards. Ammos cheaper, but its less expensive for a reason, non-reloadable and not incredibly accurate. Not worth more than .30 a round IMO.
So if you're dead set on a semi auto, I'd suggest a Mini-14. Great little guns, especially with the accu strut. AKs are great choices...but they're significantly overpriced right now. I got mine two years ago for $700 (CA prices mind you), and now the same guns are going for at least $200-300 more. Not worth it if you ask me.