I agree with stars. While the add-on system right now is usable, I've noticed that each time you upload a package that you want to have add-ons for, You have to go through each individual add-on and add it to that package through the upsell section. Seems like too much of a hassle. Some people might have several add-ons and have to go through each add-on package to set it up seems like a little much.
I think there's supposed to be a beta released very soon. I could be mistaking but I think I read somewhere that we can expect the beta around mid-july or something. Unless I was dreaming or something, I'm pretty sure I've read that somewhere.
I've tried almost every forum software out there years before I finally was able to purchase an IPB License. SMF was good but it didn't really satisfy my forum needs, next I tried a demo of Vbulletin, It was good but everything seemed too complex. Phpbb, believe it or not is my second favorite forum software behind IPB. It's free, easy to use, very versatile but still felt like it was missing a whole lot. It was when I found IPB, I knew this was it. I had a friend who had a license and we ran a few sites together but they failed. It was during those times that I found out how skinning was much simpler than other software.
In short, IPB is by far the best forum software available today. You wont regret your change. :thumbsup: