I'm looking at the mp25 I wonder if its too much movement in my 36 bow front.
Did you mean the WP25 (Jebao)?
If you are referring to the Vortech brand, they only come in MP10 and MP40.
For that size tank, I would go with the WP25.
The WP40 might be overkill for a 36gallon. And might be too bulky.
Here is a rough comparison of the max/min GPH values of the two pumps:
WP25 max: 2,000gph / min: 1,000gph
WP40 max: 3,400gph / min: 1,100gph
The WP25 is almost half the size of the WP40, but as you can see from the numbers above, performance is not cut in half.
The retail price of the WP25 is not half of the WP40 either :).
WP25 usually retails for around $80.00 while the WP40 retails for around $95.00.
From the various specifications that I have seen, the WP25 is not really the "little brother" of the WP40. It is more like a sleeker, more efficient version of the WP40 with a slight reduction in performance.
If you are buying one, make sure you get the one with the new controller. This is the one with the S1, S2 and S3 settings. The 1st generation controllers do not have these additional features.