Difference in iSRO and SRO-R

I haven't found any recent information regarding differences between those 2 versions of SRO. I started playing on Palmyra (sro-r) but now I'm second guessing my choice, beacuse the server seems to be full, but it's mostly just afk people and botters. Is iSRO any different from this ? I'm talking about JC servers here.

Thanks.

Hestia is the most populated server in Official Silkroad Online actually. (100 cap)
I don't think so is there any difference between sroR and iSro. All those differents was added to isro years ago.