Understand I'm saying this as an AR guy (I also have a Mini 14).
The Mini 14, depending on your purposes, will serve you every bit as well as an AR-15. The Mini feels handier, will take more abuse, and is less expensive to buy (unless you want to stockpile mags; those get expensive fast). It doesn't have the accuracy potential of the AR-15, but unless you're doing benchrest type shooting, I don't know that you'd notice a big difference. The newer ones are more accurate than the older ones from what I understand, but still won't quite stand up to a decent AR.
The one place where the Mini really lacks in comparison, IMO, is the ease of operation; the AR feels better to me and is superior when it comes to mag changes, charging the weapon, and employing it. If you're shooting it at the range, doing varmint control, and basic self defense, the Mini will do everything you need and even more. I wouldn't try to turn it into a budget AR (hanging rails, accessories, optics on the thing), but for what it is, it is a good rifle. Would I take the AR over the Mini? Every single time. But then, the Mini costs a significant amount less, too.