Has anyone had particular success with genie. I’m thinking of playing a fighter and the genie vessel seems good for out of combat utility by infiltrating etc and helps by picking up AoA and Hex for good damage. Has anyone had success with a similiar thing

I've played with 2014 rules but i did not multiclass out of it. It was fun and pretty useful. Flight at level 6 is solid for a eldritch blaster. Extra damage once per turn is nice even though its a small amount of damage. The level 10 ability is really sweet imo a 10 minute short rest rocks. If you can get to play with a caster with other short rest making spells you are very well covered. And yeah you can gimmick hiding in the vessel. But its pretty niche and didn't come up much. And the level 14 limited wish is just awesome.(there may be a few extra spell jammers floating around that campaign world) Though it will be weaker in 2024 since some of the solid spell options got turned form 1 action to bonus action spells. And if you make it to 17th level it gets wish(I think all warlocks should given the level of beings they are grabbing power from but it is only genies)

Thanks. So it’s good but a little niche?

The sub class overall is strong. The vessel you can hop in is kind of niche. It is a safe place to rest most of the time. But for specific situations where you want your invisible imp to carry you in its kind of niche. Until level 10 you are alone, and how often do you want to pop out alone in the middle of whatever they snuck you into. And really how often are those kind if infiltration missions part of your campaign. If you are in a intrigue campaign, or part of a thieves guild it will come up much more often. But I used it twice across a 15 level campaign to infiltrate a place. It just didn't fit the story that often.

And as an aside you are cut off from the imp or whatever that is carrying the vessel. You can hear things but that is it, so you really have to have good instructions before you hop in. Hopefully your DM wont genie wish the instructions as your familiar is supposed to be friendly to you, but that does not mean it will work as well as you planned. Like what if there is a spell keeping the imp out of the area, does the imp just circle the area uselessly, do they come up with a clever plan of using slight of hand and dropping you on someone walking in, do they just throw the vessel over the wall and hope for the best. You can't talk with them, even with voice of the chain master. So they are going off your last instructions. 

Ok that helps a lot 

6 Flight without concentration, eldritch blast with a little extra damage once per turn, at 10 everyone hides in the vessel while the rogue or wizard gets into the building or around the guards, 14 gets access to heros feast, word of recall, limited wish has a ton of uses just need make a cheat sheet.

we had one in our campaign from 1-17 constantly doing consistent damage and almost always flying during combat