Solo mostly. One of the things i like about riding is the alone time.
I don't like big groups as a norm but not against the occasional group ride. I wont lead though. Not with a lot of people. To much added stress bakes in not fun anymore.
I do have a couple people (literally 2) i feel very comfortable going out with. And by that i ean that i don't have to constantly watch where they are. It's like we're on our own solo ride, just together if that makes sense.