First of all, welcome to kiteboarding!
Second, lots of good advice here. The Glide is actually an extremely fast board. It has very little rocker, except a little towards the tips. Also, just a hint of concave on the bottom. It's a surprisingly fun board that would extend your low end significantly over EITHER of the Misfits. However, it should be an ADDITION to your board quiver, not the only one. That Misfit 146 will do much better as a "do everything" board than the Glide. And at 190 lbs, you're much better off with the 146 than the 142. As a larger human (I'm 230 lbs), I would tell you that people, in general, will tend to underestimate how much board/kite you need to ride. My step down board is a 145; anything smaller than that and I have to be LIT to ride.
So, get that 146 and have yourself a blast!