With any and all wireless, it depends on obstructions, materials, etc. I had a WAP installed about 75' and downstairs from wireless Joey, and connection was Iffy at best with a signal level at 35 or less (Installer should have never left it that way). I finally did redid some cable connections (which the installer should have done) and moved it to the far end of the room with the WJ. Signal level is now 95-100. I don't notice any glaring pauses.
I have both a Joey 2 and a Wireless Joey. I can't really comment on the range of the Wireless Joey, as the distance between mine is pretty short. I will say that The Wireless Joey in my setup is solid, and easily as fast, possibly a tick faster in operation than the Joey 2. On both Joeys, you'll see lag going in and out of menus, dvr list, etc, as compared to the main Hopper, but both are usable. Trick Play can sometimes be inconsistent on Joeys, but I've never noticed a specific lag in hitting the functions you mention.