idk if the eclipse is a better sub, but ur mtx is 250 more rms power handling. the eclipse is rated at 500 rms and 1500w peak. n if im remember correct the mtx 9500 10 is 750 rms
I don't know who rates subs by there quality because of power handling but in my honest opinion the eclipse is one amazing sub.
That exact sub was my first sub that i had ever had when i was 16, loved it to death and it did great and sounded sooo clean. It will eat whatever power you throw at it as long as its installed correctly and the amp is tuned right.