When somebody asks on this forum how to choose a dojo, they are always encouraged to go check out at least a couple of dojo's before they choose. I think you should do the same and go check out the other dojo. You should give the new teacher a chance as well. Find out what dojo suits you best.
I know it's difficult but if you can leave out your old knowledge and look upon both dojo's with an open mind, then you will probably know were you would like to practice.
Just out of couriosity: what style does this new teache practice ? I have come across a few different teachers all under the Aikikai, but with very different style and focus. My guess is that you will quickly adapt to the new techniques if you just try to enjoy practicing.