Honestly, I think the slow speeds are due to the radio in the Fascinate.
I did some very non-scientific side by side signal tests with my Fascinate and Droid one.
Sitting right next to eachother, the Fascinate always had 2 or more bars fewer than with the D1.
This result was the same regardless of the area that I was. By the way, I am in northern New Jersey, close to NYC, which has excellent Verzion coverage. I hope that this gets addressed in a future patch.
I have seen the bars fluctuate from 4 to 1 to none and back again when doing a series of speed tests; for me they do not translate into data performance at all. If anything, the bars drop one or two notches when the speed test starts but they rarely correlate with a fast speed, it's time of day and local infrastructure that seem to play the biggest role in my tests.
I thought 600 or so was good (i get it from any area with 3g coverage early in the morning when theres light traffic) but that was in Ohio. This week I am in So Cal and the 3g speeds here, off peak, are amazing. I am getting 800 to 1200 download from any 3g area unless i run the test during primetime (5pm to midnight or so on weekdays, any time noon to midnight on weekends).
The bars are a rough guide, but speed tests tell the story. Honestly I have to say I'm not disappointed in the radio; as long as I'm not out in the boonies, or inside a bunker, I can test at 400 or faster.