What do you mean by buy some M22ti's to complete your M50ti's? Where would the M22's go? Where would the M50's go?

Your question has lost me.

Regardless of that, from what you're describing, you want a pair of M60's. I think if you went from the M50's to the M22's you'd miss the fullness you get now. The M60's have exactly what you are describing you want. All the depth and lush fullness of the midrange and low end, but they also have crystal clear highs.

How long have you had the M50ti's? If you haven't gone too awfully far past the 30 days, perhaps they'll still let you return them. Then you'd only have to pay the difference for the M60's. It's worth asking.