I have the gyre xf150 on my 90 gallon and i love it! I really like the linear flow. It keeps the water surface disturbed, no dead spots, keeps areas behind rock work clean. Only downside is the gyre is less controllable then the vortechs, you only get a constant, pulse, and gyre mode. If you have an apex, theyre coming out with ability to connectthe gyre to the APEX and this adds a lot more control. The vortechs are awesome too, and have great features but when comparing price at $300 for the Xf150 and $350 for the MP40, they gyre destroys the vortechs with how much power/flow you get get for the price. IME the xf150 is way stronger and more powerful then the vortechs but has less control/features.
It kind of just comes to preference and which one you like the look of better because they are both top of the line products and you would more then likely be happy with either one