I found Spark in two spots in Tampa, here's a screen shot of one of the Speed tests
you can do a field test to see what band your phone's connecting to at the moment by pressing *3001#12345#* and selecting serving cell info
I'm at 119th and Quivera in Kansas City, KS (Overland Park area) and barely seeing any signal inside my home, and outside I see maybe 2-4Mbit speeds. Zip code is 66213.
MOST DEFINITELY NOT SPARK SPEEDS.
I can sit on the Sprint Worldwide Campus down the street and STILL only see 4Mbit.
Ok everyone, Spark IS available for the Iphone 6. It does have band 41 because this is pretty much what every other country is going to. When you see LTE networks being built out through Canada and China most of the spectrum being used there is under the 2.5 ghz as well. They use the same technology that Sprint is using to build out their network, TDD LTE which is a Tri-band LTE using 800, 1900, 2500 mghz.
To address the issues with speed. You may see some lapses in speed and reliability for a little while unfortunately. Sprint is focusing on pushing out it's 2.5ghz spectrum in denser waves than what has already been released. This is the difference between Spark, and Spark Turbo. Once these upgrades are pushed out the building penetration will be better, so indoor signal will increase, and so will your speeds.
You should be happy with the 2-4 Mbps, stay away from Antioch, we have no data except when I park under the tower at the OP Fire Training Center. Sprint is admitting to an issue with the phone, however if you read the posts Sprint Spark has had issues for some time with tri-band phones.
SprintCare, if what logank09 said is true, is spark expected to be finalized anytime soon in this area? I would expect the "Sprint Campus" to have support at least expected at a reasonable speed? 4Mbit is utterly pathetic service for LTE, as HSDPA 3G is faster on AT&T.
Half the time I can't even make phone calls inside my house because signal is so poor.