On the ETFC platform subject , I have to say .. Etrade Pro has been pretty darned clean in the few months I'm using it. It's always important to have your computer up to snuff. And, clear the cache regularly.
I used to trade w/ Pro and had a number if issues. These past months have been excellent. You can always call tech support to ask them to help clean up your computer if you are finding entering orders sluggish during busy times.
Plus, you get DJ news which is a big help.