Only T3 RvR for Tazelbain, no point in moving up until Mythic gets its act together. Stackhouse and Fira are my alts if you need me. Maybe start another one.
T4 is inevitable, and it doesn't really change that much. After breaking through Tor Anroc I thought I was gonna have a different map. 20 Serpent Passage later, I was bored again.
A couple of the other ones launched for me (after de-queueing for SP) The Outdoor Dwarf one with the bombing 'copters almost never had any Destro in it (if they did, they left quick) and the Skaven tunnels were always a blowout for whichever side had more dps. None of the other 3 ever launched.
After everyone just started the Magnet/Rift AOE stuff, it wasn't any fun at all in SP. Sure, I could grind to 40 and get Fetch and fuck with other people in a similar way, but why?