I'm guessing you are riding the mtb on the road and not on the dirt. There is zen in dirt too ya know

Anyway, I was in the same position as you, but I had bought a 'hybrid' to ride to work and realized it was just like riding a mtb. I then got slicks. What a difference. So my point is, it sounds like you might need something in between for now, how about putting slicks on your bike until you find the right bike? Just a thought....Unless you are riding a mtb with slicks already!