In my opinion, Mootools is more like classic programming with objects
and classes (oop).
In my opinion, jQuery is more about visual effects. Sure you can write
a great program in ether jQuery or Moo. But given the choice I will opt
for Moo any day of the week. In my opinion Moo is more powerful and
makes better use of familiar programming constructs. But don't get me
wrong, both are powerful in there own way.
With all that said and with my bias twords Mootools, jQuery does has a
huge user base and a ton of examples/tutorials, so it may offer more of
a positive out-of-the-box experience. However, I have always found this
mailing list to be very helpful with any questions.