Yes, this is indeed an old debate! I happen to own both, a Mini-14 SS Ranch, wood and a Mini-Thirty SS, synthetic.
Right off the bat, you should know that there is no such thing as a 'non-Ranch' model of the Mini-Thirty. They are all Ranch from day 1.
Also know that there are MANY more aftermarket goodies for the Mini-14. Ammo in my experience has been about the same price for either (if you buy the bulk Russian garb).
Like Grinch said as far as hi-cap mags, but like Greg1911 said as well, you live in Kalifornia

P), so the point is moot. If you do get a Mini-Thirty, your source of 10 rounders is johnmasen.com
Yes, the -Thirty has a bigger, slower round (7.62mm), but it's functionality as a long range, or plinker is limited. The ballistics, as Bill has pointed out in the past, kinda suck. Yes, it makes bigger holes, but I find that holding it on-target for a rapid succession of shots is much more difficult than with the Mini-14. My feel of it is that it's more of a CLOSE quarters combat round.
The .223 round makes the Mini-14 easier to hold on target with rapid shots, you can carry more rounds of ammo, there are more parts on the market, there is much more of a knowledge base (this site for example). One drawback of the .223 round to consider is: it is a PENETRATOR. To the max. This could be good or bad, depending how you look at it.
Also, if I recall correctly, the coroner's report says that the .223 round actually does more damage since it flips around more upon impact than a 7.62mm round does. Your mileage
will vary on that comment.