Honestly, it's all about your location.
In areas with no Network Vision upgrades and ancient T1 backhauls, sprint's 3G is going to basically be unusable. While the EVDO towers can easily handle 1.5-2mbit of speed, the backhaul is so clogged that you are lucky to get 128kbps. (.1mbit)
I disabled the 4G Radio in my phone and did several speed tests on EVDO. This was in peak usage time (~1PM). I live in Maryland and I am in the Baltimore market rollout. This is a Network Vision tower, with 4G LTE I am connected to. The backhauls are fully upgraded with fiber. My speeds mostly sat around 1.7-1.8mbit. Enough to stream music on the go, load web pages, stream 360p youtube.
If you live in an area that is getting a 4G LTE rollout, the 3G speeds will definitely increase - and will probably be equal to those 3G speeds of the other CDMA provider - Verizon.
Then I enabled the 4G radio in my phone, ran another set of sets. About the same time (~1PM.)
My average during peak times is anywhere from 5-9mbit down, with 3-5mbit up. Easily enough to stream HQ Music, HQ Youtube, quickly load web content, and even some HD netflix worked without problem.
During off-peak times, I easily speed test at 15-16mbit down, and 7-8mbit up.
My favorite has to be off-peak times. After about 11pm, everything is amazing. I can do multiple things online without issues. Tether to my PC, stream music, download files, ect. I've hit 16mbit down pretty easily, and I'm actually pretty far away from the tower. My RSSI is generally about 110-113dBm, which is getting to the edge of usability. I never lose my connection. (75 is right next to the tower, 120 is the edge of the signal.)