Welcome back to UO
I had the same feeling with every other MMO out there, played basically the same as you and some more over the last 8-9 years and after the novelty wore off they are basically all the same with different looks. No room for creativity, no sense of risk/danger as here so I decided to come back where it all began for me as well.
Oh and a little tip when you want to convert that trial to a full account or at least have Stygian Abyss access as I had a bit of trouble with that.
I opened a 2nd account and decided after feeling happy on Siege that I want to stay for good and wanted to convert my trial to a full account because I would like to train mysticism so I had to upgrade to SA.
Phoned 3 times customer services, tried webchat as well asking them to activate my subscription which I already created and unflag the account as trial. They said they couldnt do that, against their policy etc etc. When I tried to buy the upgrade on uogamecodes it wouldn't let me so I was a bit miffed.
I then went ahead and bought the upgrade from the EA online shop instead and could apply it to my account. Now I have access to Ter Mur, can learn Mysticism but am still in trial, so no Felluca dungeons which is a bit of a bummer on Siege

So I opened a ticket now telling them that I bought the upgrade, could apply it but cannot access the Stygian Abyss dungeon which is in my upgrade, I hope that convinces them to lift my trial
