MPFP in his haste to respond to every post in the forum did skip over a few things
MP2 - internal controller stay away from it. Too problematic.
MP3 - internal controller is more reliable and easier to replace
MP2 - with external magic controller peaks around 1250 watts
MP3 - peaks around 1500 watts
MP2 - thicker
- front offset to accommodate disk brake can sometimes cause issues of rubbing on narrow forks
- rear wheel easily accepts 6 speed freewheel.
MP3 - thinner
- less offset on front motor makes for less fit issues
- rear wheel easily accepts 7 speed freewheel
MP2 - wire exits motor through axle and can be damaged easier
MP3 - wire exits through side of motor and is better protected
MP2 - reasonably quiet but does have a "pinging" sound on start up
MP3 - quieter with no "pinging" sound
MP2 - with external controller requires more wiring that can be intimidating to first timers
MP3 - very simple and straight forward hookup
MP2 - external controller location and wiring can look a little messy
MP3 - wiring is very simple giving a clean look
MP2 - proven performer for power junkies who like to use more powerful third party controllers
MP3 - becoming popular with power junkies as well due to ease of converting to external controller
and the fact they are more powerful to start with.
MP2 - external controllers are more reliable
MP3 - the MP3 is far more reliable then the MP2 Internal was. But there are still some failures.
And yes there is a large bearing on one side of the motor in the MP3. Because of the desire to make the controller very simple to replace the motors are designed very differently. There have been a few issues with MP3 bearings posted in the forum but keep in mind most people don't come to the forum after a purchase to say they are having a nice day. I have sold a lot of these motors and still not one bearing issue reported to me from a customer. I do have spare bearings in stock incase this issue arises but not enough to sell them.
To be 100 percent honest the most dominant issue with the MP3 is the controller but at this time I still feel the level of failures is acceptable. I know there seem to be a lot of MP3 controller issues in the forum, but again most people don't come here for fun. I bailed on the internal controller MP2 not long after release and am pretty sure the reason the MP2 externals even exist is because I stopped buying internals and requested external versions.
I also mentioned issues with motor rub on some front forks with the pies. This is not that common and its usually poorly designed forks that either taper in almost immediately above the dropouts or have the dropouts wielded in the Center of the fork arm rather then have the dropouts flush with the inside of the fork arms. This issue can usually be corrected by adding one washer on the side that's too close. I have not had anyone that could not make it work.
Gary
PS Sorry MPFP, I was just poking a little fun at your expense, but that was a bit of a hasty answer