said by kamm: It's not a firmware upgrade, your phone's chipset isn't capable of speed's higher than 7.2mbps, every HSPA upgrade requires need chipset's in the phone. I'm a telecom engineer so I am pretty sure I know the difference's.
Instead of making up silly, illogical claims why don't you read up on the subject?
HINT: HSPA = HSDPA+HSUPA (and even HSDPA means up to 14Mb/s if I remember correctly.) And HSPA+ is still HSPA, it's just an upgrade for speed up to 50+ megabit via MIMO.