After more research I have been hearing that the unlocked 9900's running on AT&T run at the same speed whether they show H+ or 3G. I would appreciate seeing your speeds on these speed tests - iPhone speedtest
or Mobile Speed test
I have a 9900 from Mexico with OS 188.8.131.523 on ATT BES plan showing 3G but within AT&T's H+ coverage area with wireless shut off. My results on Mobile Speed Test are between 800 and 1000 kbps and on DSL Reports between 1000 and 1300 kbps. Interesting that if I increase the file size on Mobile Speed Test from the standard 100kb to a 2 MB size my speed now shows around 9,000 kbps.
How are your speeds?