I think you're expecting a bit too much from 3G improvements. 4G LTE enhancements, especially with up and coming tri-band deployment will really be where the improvement is at. Also, judging by the sponsor maps, all of the improvements in Madison have been 4G only, meaning that the new 3G panels and RRUs have not been accepted for activation yet, probably for interference concerns with legacy Motorola equipment, so the 3G improvements might not be as large yet as they will be.
The FCC documentation for the LGD820 (which is rumored to be the Nexus 5) has it listed as capable of using all three LTE bands on Sprint (B25 800, B26 1900 and B41 2600). The LG G2, as well will offer triband coverage on Sprint. If you can wait, the release date of the Nexus 5 should be in mid-October. I think I'm dropping my HTC One off on ebay and grabbing one of these guys to take advantage of the huge amounts of 2600 being deployed in Chicagoland right now