couldnt really tell you. im online with my phone right now because my cable internet is down. i hardly miss it though, the edge internet is just fine for general browsing. i can even look at graphic intensive sites without much headache, the flow is slower but still smooth.
messing with the port settings didnt seem to change anything for me, i always get 20kB down and 10kB up, no matter what. thats a lot faster then a 56k modem though, so im not sure why yours doesnt run faster.
it shouldnt be painfully slow, and it shouldnt keep hanging up on you like that. mine works very smooth, but i wouldnt be surprised if it is 400+ ping times. thats expected, its over a cell phone service.