What's the difference between the power mag and the power plus mag? My TRP runs great on ETMs but I want to add a few 10 rounders.

I've got both but the power mags are a few years older than the power mag +.  

The power mag plus fit the bevelled magwell out of the bag.  I had to dremel the top angle of the base plate on the regular power mags to fit.  It could have been just because they were older but either way, it only took a few seconds with the dremel to make them work.  Also, CMC doesn't, or didn't at the time, sell the plus base plates separately.  I tried to get them before I broke out the little drill.

Power Mags Plus have a special follower that won't tip forward on the last round.  

From CMC website:

"The Power Mag+™ follower is such that it is more stabilized and remains within the confines of the magazine tube. Power Mag™ follower jumps forward at the point of engagement to the slide stop, yielding the most positive engagement possible as compared to any other follower design in use today. Over the years our many federal law enforcement and military special ops customers have informed us that they are not only extremely concerned with feeding, but also reliable slide lock upon last shot fired (notifying weapon empty). Power series mags have achieved such great reputations because they excel every area function and service life. The two follower designs accomplish the tasks in different ways. Since in some cases the Power Mag™ follower can make contact with the pistol receiver and the Power Mag+™ cannot, for pistols with aluminum frames we recommend the Power Mag+™ series magazines."

Hey thanks, I guess I could have found that myself. Sorry :)

No problem.  I only have Wilson 10 rounders but have been wanting get a few of these 10rd Power Mags myself.  If they are anything like their little 8 round brother then they will be good to go.

I got one in today, gonna try it next week before I order more.  Found a seller on ebay with a good price and free shipping. I'm me and I will send you a like so as not to violate forum rules.  I'm a Wilson guy too, 8 round ETMs.  I wanted to try some 10 rounders to put on my vest pouch.