Acratech GP Ballhead advice

I am looking at purchasing a new ballhead, and have narrowed it down to between the Acratech GP and the RSS BH-40. I very much like the way the Acratech can be inverted for pano use, but I would like to know if many people have this ballhead and use it in this way, and if they are generally happy with it's overall performance? Any feedback about this head would be greatly appreciated.

I have that ballhead and am quite happy with it. I use it on my lighter pod, with a RRS BH-55 on my big pod. If I had it to do over, I would not pay the big bucks for the RRS and would only go with the Acratech. It holds well, works smothly and is light. I use it for both large format and a Canon 5dII with a 70-200 on it. I hope that helps.

One of my shooting buddies has the acratech, and I've borrowed it a few times - a very good piece of equipment. I'd be a little hesitant to use it with my 500, but it held the 300mm just fine. Surely would not have a bit of trouble with smaller landscape or wide-angle lenses.
Hope this helps.
Sandy

Thank you Harley and Sandy for your feedback, it certainly does help. I'm still not sure about how painful the inverting and changing the plate will be on the GP for pano work, and I may consider the GV2 with a leveling base for the amount of pano work I'm planning on since it doesn't need inverting. Great to hear the GP's performance stands up though. Cheers.

Sorry guy's. I've just realized the Acratech head won't fit in my tripod bag when attached to the tripod. I should have checked the dimensions earlier (my bad). Looks like I'll probably go with the RSS BH-40 at this stage.

What about Markins Q3 of PhotoClams? I have Markins very happy with it, for my light equipment (Travel). And I've heard very good things about PhotoClams, Cheaper and good quality!! just food for though!!
Hope I am not confusing you.

David honestly better change the bag as the Acratech head are just great piece of equipment.