It is a challenge. And a safe one to take too. The only safety related issue is to be very carefull who is behind you if you have to increase your thrust one the running engine. So as a rule, I avoid it in small aprons.
The other (non safety related) danger is loosing face. I must admit I had a couple of almost embarassing moments while I unexpectedly was asked to hold position by ATC on an upslope part of the taxiway. Practice and experience makes perfect. Especially now that my SOPs allow me to restart the engine if I get in trouble. Better that than a tug....
