When I'm in the lane, cars can't see me when they're right beside me so they sometimes move in on me -- no big deal if you expect it. You do need to mindful of getting pinned against curbs, parked cars, and the like. My description makes it sound scarier and more dangerous than it is.

Overall, I get cut way more space and treated significantly better than I do on a road bike because people keep mistaking me for being handicapped which can be simultaneously funny and depressing.