I used to subscribe to RC Driver but they have gone way more in the direction of a newbie based magazine within the past couple of years, so I dropped my subscription.
I get RC Car Action, which I agree with previous posts of its 98% ads but their reviews are fairly in depth.
Xtreme RC though is by far my favorite. They are the most honest of all the RC magazines in my opinion (they will actually give something a negative review, something that I have never seen RC Driver or RCCA do), their tech articles are good, their reviews are the longest and most in depth, and of course, they have those hottie professor girls in their tech Q&A section, always a plus when you could care less if its a "family oriented" magazine (What family reads a magazine together anyway these days? lmao).