most i've towed was a u-haul 6x12 enclosed trailer about 300 miles round trip, estimating about 2800 lbs gross cause the thing is 1900 lbs empty plus all the crap i put in there for my sister's move.
i turned off O/D and went about 60-65 mph the whole time. it handled well, acceleration was slower than normal but it took it like a champ. stopping was fine, of course the big u-haul trailers like this have surge brakes. when accelerating on an on ramp i spent a lot of time in the 4-4500 rpm zone. when passing i took the rpms up pretty high, but never once did the coolant temp move above where it sits all the time normally. gas mileage sucked but i didnt encounter any issues on anything. the transmission (auto) shifted just like i would expect it to under load, and performed admirably.
towing lighter than that was easy. i wouldn't tow anything more than 3000lbs gross, as this little iddy biddy engine has to work pretty hard for it. no truck should tow at its max anyways, which for the 2nd gen XEs is 3500lbs.
it's fine for occasional sub-3000lb towing.