I'm using a staff as my mesmer right now. Not sure if it's better than Sceptre + Focus, really. I've played too little to be able to tell. The basic sceptre attack seems better at placing clones close to the enemy so you can blow them up, though.
My FFRP characters. Avatar by Kid Kris. Sigatars by Gulaghar, Kid Kris, Zefir and billtodamax, respectively.