There is a new one coming out soon from a highly popular developer. I can't remember the script name. I use both of the scripts you listed above and I think only phpArcadeScript continues to update their script. Not sure about gamescript as the company has been sold several times the last several months.
i will go for phparcadescript, since i m one of their first customers, their script is very easy to customise and its cheap. I don't have gamescript currently, but it seems the owners takes care of their business now, cuz the new version keeps coming out.
Try to check out their forums and u will see which one is better.
I was a Gamescript customer till it was sold to John D and he dropped the ball big time on it with the yearly license, encryption, and lack of support..it went from #1 to last place IMHO.
Gamescript has the hinderence of being encrypted, lacking in features and being passed around from owner to owner like a unwanted redheaded stop child.
phpArcadeScript had been under the same owner/developer from the start. Has consistant support, has a ton more features then Gamescript and is consistantly being updated and is NOT encrypted in anyway. It is also CHEAPER.
IMHO phpArcadeScript has left Gamescripts in the dust.
Gamescript has been updated a lot recently. It appears to be a really nice script. I'd buy it in a second but it's encoded. Unfortunately, I'm a customer of shockscript which is an encoded script. They haven't released a new version since forever and it's really starting to fall behind. I'd like to modify it and add new features but since the whole admin area is encoded, I'm stuck.