@Arc676 yes - the speed slowdown isn't nearly as bad on modern USB drives - especially if you have USB 3 throughout - as it was in the old initial Intel days or PPC days.
It's enough a slow down to get you to know it's not horrendous and that your software works. It also is a nice speedup when you get it on the main storage.
OMG I love Safari 9! Pinned tabs and Cmd-# switching for tabs have it on par with Chrome for features I care deeply about. And it's so faaaaaaaast! Also, I swore I wouldn't El Cap at home but I El Cap'ed my iMac and it's actually fine. Possibly a little faster than with Yosemite.