Jonolau...I thought you had already gotten a DNX 9! You are starting to follow in Craig Clark's footsteps w/the summer of endless decisions...
Yeah, the bargain price on the M-Fil is a sweet bonus...
As I think you know, I demo'd the DNX 9 and M-Fil 300 amongst the many I sticks that I hit with. They were my last two sticks that I chose between, and both performed very well for me in all areas.
After a few days of hitting I was on the fence between the DNX 9 and the M-Fil 300...the DNX had a slightly more solid, comfy feel overall than the M-Fil 300, but both felt very good to me. I did better at the net w/the M-Fil (found it more manueverable, better reaction volleys, and somewhat suprisingly, slightly better on drop/touch volleys), and served better with the M-Fil as well. I use a variety of serves (flat bombs, slice, and kick, lots of varied pace) and was able to dial in my serves w/the M-Fil much easier than the DNX 9 for some reason. However, groundies and serve returns were somewhat more penetrating w/the DNX 9 with less effort.
In the end, I think the main deciding factors were that I found I had the best balance of power/control w/the M-Fil, had better results at net, and my serve came online very quickly with it.
Definitely recommend the M-Fil 300. Also the RDS 001 MP (but that's getting right up w/the DNX 9 in terms of $$).