On my Inmoov robot I have every type of servo,:) some older and some ez-robot servos Hdd and they all work, the ez-robot servos are the better choice as they are quiet, and strong.  there are no issues using a mix of servos

They operate essentially the same. The HD ones will be louder, and I believe a little less accurate. There will be nothing that you will do differently.

Thanks!  Didn't want to crash and burn one servo in the midst of JD doing Rock Climbing!

hold up - rock climbing!? Tell me more!

Let me get this thing working first... ;~}