mp10
i have mine in a 55 gal seahorse/refugium tank.
the pluses are: adjustable speed, no heat transfer, feed mode, night mode, accidental disconnect safety mode, various wave program--you can program to suit your need, option to have a back up battery--don't know how long but if they claim it would do 24 hrs. on the mp40, i would assume perhaps twice that on the mp10?
the minuses: can be loud/whiny at certain wave mode--not good in the bedroom or a quiet room, at full throttle, the outside housing gets quite hot after a while. if the electricity goes out and it's not connected to a back up battery, night mode need to be reprogrammed...which you have to do it at the time you want the night mode to start, ie. if your night mode starts at 2 am.....you gotta stay up to program it then. if you accidentally change the custom programmed wave mode to other mode, you need to re-program the custom wave mode to tune in the wave again. in the beginning that's not as easy to get the optimal intensity and frequency but with some experience, one can re-program it in just a minute or two. the programming is not very intuitive.
overall i am very happy with the
vortechs....mp10 and mp40. the pluses outshine the minuses. imo, for the money, nothing comes close to it. the only question i have is longevity....i have the mp40's for less than a year and mp10 just a couple of months.