I play OSI and have the boosters and expansions. after those I only pay for one account and don't spend any more RL cash other then the subscription fee.  Only time I'll buy stuff is new expansions and boosters.  I took a break for 5 years from UO, and tried to get my fix on freeshards, i tried a few, some were pro macroing afk some were very against, some didn't want to know but wouldnt go after you.  And for my $0.02 OSI is the only way for me.  And i play Pacific, Atlantic and Siege.  and as far as addictions go I couldn't be happier. Unless someone could pry the keyboard away from my hands and erase UO from my mind, i will always stick to OSI until they shut it down.
 Cheers!