XI's trusts are way better than XIV chocobo companions. Some are as good as PCs. The vast majority of them have assigned jobs, and access to some subset of the actions available to a PC with that job. The better trusts can use all the spells and abilities that you would expect a competent PC to use as that job, so tank trusts can actually tank, healer trusts will Protectra and Shellra at the start of battle, support trusts will Refresh the mages or Haste the party/sing/whatever, DD trusts will close skillchains that you start. Some will even wait to see what weaponskill you like to use, then for the rest of the time they're out they'll use weaponskills that you can skillchain on.
The limiting factor in XI is unlocking those trusts that have all the actions and gambits that you are looking for. Some of them are only available during recurring event periods, so you could go 6 months to a year without being able to get one of the time sensitive trusts that you want.
Edit: oh, I think I misread your chocobo question? I don't know how trusts compare to chocobos (I didn't think we could summon chocobos to combat in XI?) Trusts in XI take up party slots, though. So you could summon 5 trusts if soloing, or your adventuring companion and 4 trusts, or you could party with two friends and summon 3 trusts.