I made the experience that dungeons with Trusts are faster as a DPS if you count the queue time. They take about 26-32 minutes (I always use food at the start and by the last boss the food buff is either almost over or it has like up to 5 minutes left. With real people it's like 20-25 minutes on average, after the wait time of 15-30 minutes. With Trusts you know what you get, with real players you might get a single pull tank, a zero DPS healer fishing for Freecure procs, or DPS that do the same damage as the Trusts. And most times you really get those kind of players in leveling roulette.

It's annoying that when you pull extra, the Trust tank takes so long to aggro the enemies, while the healer gets beaten up because he healed you. Or when you're the tank it's annoying that when you pull, the Trusts start attacking immediately and get left behind when you pull more. And of course they are slow and stop everything during mechanics. But other than that it's a nice way to level, or see the dungeon without being rushed through it.

It would be nice to unlock them for low level stuff as well, but it would need a very good incentive to make people do those dungeons with others instead of only Trusts.