CDMA EV-DO Rev A is older and therefore slower than HSPA+ (at least as I have read). What helps VZW survive is that they've turfed more of the country with their towers, which results in them having more stable coverage. But more stable coverage doesn't equal faster service.
BL.
There, fixed it for you.
EV-DO Rev B is on par with HSPA+ and Rev C would have been faster than LTE. Rev C was dropped when carriers chose to go with LTE and stop the standards fight (3GPP aka GSM vs 3GPP2).
To answer the original question. I regularly see 20-30 Mbps on my iPhone 5 on Verizon. It can get slower (8-12 Mbps) due to congestion. A larger percentage of VZW's customers are on LTE compared to AT&T at this time.