iPad 2 running iOS 7 with Blue Yeti Mic
Probably too late but for anyone else who may look for info on this:

I have used the Blue 'Yeti' to do quite a lot of recording into Garage Band on an iPad2.
  don't know anything about the other mic you mention but the Yeti is great for that price range in my experience. 

I used a Belkin powered USB hub (+CC kit)as a work around successfully until one of the recent iPad updates (I haven't used the mic for awhile til recently so not sure which update), but now it doesn't work anymore. 

the message "device draws to much power" or something, remains and the mic doesn't work...

didn't think to try without the hub in the chain..