Since we know that AVCHD is not a a standard and one AVCHD from one camcorder may not be the same as the other AVCHD you get from another camcorder my parting advice is to make sure of the return policies on the products.
This area of transfer and edit of AVCHD is a minefield for many reasons and before you think "why doesn't this all work now?" it's because of many reasons but the one I bumped into at the office (we work on DVR code) is the patents. So while VLC PLAYER is lucky to be from a country that does not recognize that patent, other authors can't craft such a solution and get it on the Apple store.
I mentioned the WiDrive because I had such and was tossing out all ideas such as it could be used as a bridge from the camcorder to the HDD you noted. That is, if you didn't figure it out, camcorder to WiDrive direct, over wifi using the ipad to the GoFlex.
For me all this is interesting stuff and my thought is that I would bring my laptop.