I do quite enjoy 1v1, but I'd appreciate having something like the SC2 matchmaker's ability to select up to a few maps before queuing to make them extremely unlikely to appear.
I don't particularly enjoy sea battles, and for reasons I can't quite put my finger on, I don't particularly like Shifting Sands either. Knowing that I'm not, or that I'm probably not going to play a 1v1 which would force me into these situations, would go a long way to improving the matchmaking experience from my perspective.
The other main problem as I see it is that sometimes you just get too wide of a skill gap. I don't mind playing against better players and it can be quite instructive, especially if they're helpful enough to give advice after the game, but playing against much worse players can leave me feeling pretty bad.
I don't know of an easy solution to the second problem, as it seems like can only be fixed once you have more than two people in the queue.