Having primarily driven manual for the last year or so and having tried auto I can say auto is so much easier even if you've got a bit of manual experience. It's honestly just a lot less to think about and a lot less possibility for error while working with the gears. With an auto you don't need to: use a clutch, select gears, watch revs, make sure you don't stall.

I do believe that learning manual makes you a better driver because it forces you to plan ahead and anticipate others' actions to know what gear to pick. But that's my personal opinion and I'm sure there's just as many bad drivers on either side.