Here's mob stats as fas as i've been able to find out (health stats only, and xp seems lineair to the health):
-general   1x
-champion  2x
-giant     15x
party monsters
-general   8x
-champion  16x
-giant     120x
most of this is quite easy to verify: base attack, and count.
For the party Champions, you'll notice its about 1 mob more xp and health than a giant, which is the conclusion if my "research". 
 
 Greetz,  MementoMori (Babel)