I've tested a variety of HSPA+ devices on AT&T's networked and never even approached the HSPA theoretical max of 14.4Mbps, let alone HSPA+'s max. More commonly, I'd see speeds of 1-4Mbps down. Never any more than 4.
In Canada it's not hard to get 10-13mbps down speeds with HSPA+ devices, But that is with a 21MBit device (USB broadband stick). All the carriers in Canada are now 21.6MB HSPA+ and converting to 44MB HSPA and 75MBIT LTE. What G would you call that?
I think it depends largely on the pair of devices. Both the cells and the local device need to support higher speeds. Here in NYC I have tested 3 HSPA+ devices and only one of them gets close to 14.4Mbps on AT&T (probably due to radio differences in the devices). Outside the city, it's never that fast (probably the cells are slower).