Hmmm...I don't know Magness the only bonuses they get are:
+1 to search
+2 saves against enchantment magic
Immune to sleep
The search and sleep are almost useless I think (sleep doesnt effect you over level 5)
On the other hand I just checked the manual and it appears the hold spell series are enchantment magic as well as the "charm" series so that one may be a bit more useful than I thought since one of the most annoying (and deadly) spells an enemy is likely to cast on you is a hold spell.
Even so its tough to turn down an extra feat and extra skill points for. Even if you have a low skill person this would likely double his skill points perhaps making it possible to gain some useful cross class skill.
I do admit its perhaps worth a look at the half breed tho rather than dismissing it out of hand...
