I had Unicom for years and the connection was always steady solid. Now that I'm downtown Beijing, I've discovered the evils of Gehua Cable.. it's pure utter crap and unreliable! The connection just decides to die at random hours of the day.
I'm going back to China Unicom next week for their 4MB!
Higher speeds don't really help your browsing speed as far as international sites go: The bottleneck is at the GFW level and nothing can help you there. Downloads will improve slightly but again, mostly within China.