By no means am I a fanboy of Sprint however I used to get 3-4mbps on LTE for VZW but now that's what I get on 3G for Sprint. Most of the time I am in an LTE area averaging at 25mbps.
I do think that since I am on an MVNO (FreedomPop) and not the actual company there may be more bandwidth allotted to FP and with the PRL I have and that could be why my 3G speeds are decent.
Once Spark goes live in our area I will expect really fast speeds... Yay.
One thing tho. Sprint's call quality is terrible in areas with low signal on my dad's phone. I use VoIP so I don't need to worry.