I find the Slingbox HD does pretty well at low bandwidth. My old Sling A/V isn't too bad either. I haven't tried to watch it on my Verizon Broadband card in a while so i'm not sure.
Honestly it'll look better on 3g. And video performance and buffering issues are two different things. The video performance changes depending on bandwidth.
Jahntassa What, I can have feathers Premium join:2006-04-14 Conway, SC kudos:4
Well..I mean its kind of hard to answer your question without testing it on the phone / route you're using..I'd say just give it a shot and see how it goes.