i like the team up feature; as someone who can't play during peak times and usually has trouble finding groups, it's quite useful.
that said, the allusion to this feature being required at some point in the near future makes me very uncomfortable. as someone who soloed the game through azteca and khrysalis (save for the ridiculous cheat dungeons), i enjoy my own company from time to time and i don't like being forced to rely on other people. the main story arc should be doable for everyone, including solo players.
yes, group play is fun at times, but it should never be required. the day that it becomes anything but optional will be the day that i leave and don't come back... and i know i'm not the only one.
I think it's a good idea for those that quest at later hours when nobody is really on and they can find someone to do their dungeon without having to check each individual realm.
It's great for that, I believe.
As for as the recall dungeon, I mark my spot so that's really not much of a help as it makes you walk the whole way back from the beginning at Tartarus, doesn't really save time honestly. I thought this was going to be the better feature, but I haven't found it useful at all yet, but perhaps others have.