Sprint's Spark: It's Fast but No Multi-Tasker
Sprint says it is focused on battery life, coverage, and performance for its Spark devices over the ability to talk and surf the web at the same time.
Consumer Reports found that phones on the Sprint Spark network can't do simultaneous calls and data sessions. The publication found that data-dependent apps stopped functioning when a call came in or a user made a call.
Light Reading asked Sprint about this: "Sprint Spark devices leverage eCSFB technology (enhanced Circuit Switch Fall Back), which enables single radio functionality in the handset," a spokeswoman explained in a email.
She continued that using a single radio at a time gets better performance out of devices that can utilize the Spark network upgrades:
- This allows Sprint to leverage the many benefits of Network Vision, including the ability to utilize multiple CDMA and LTE spectrum bands efficiently. Although simultaneous voice and LTE is not supported on new Sprint Spark devices, it does provide improved coverage, quality of voice and data service, as well as improved battery performance. The devices will support simultaneous voice and data on WiFi.
So potential Sprint Spark users -- the upgrade is currently available in 24 markets in the US, most of which are big cities -- have a choice to make: Do they need a really fast connection when not calling, or do they need to multi-task? Users have so far been finding 60+ Mbit/s speeds on unloaded networks, while Light Reading saw speeds of up to 27.27 Mbit/s on a busy network in New York City. (See Fanning Sprint's Spark in NYC and Sprint: LTE TDD Speed Boost Coming Soon.)
— Dan Jones, Mobile Editor, Light Reading

So, yes, I could see not needing the dual-functionality if my iPad was near, but stepping out from a meeting, as a passenger in a car, in line to board a plane--wow, actually, as I'm beginning to do the inventory, this is a bigger need than I thought!
Anyway, I believe the goal of all the wireless companies is to eventually go to Voice over LTE (VoLTE). In that case, voice is just another data packet, so voice and data will work just fine on all LTE phones, Sprint included.
In the mean time I personally prefer the extra battery life. But if I were a tech that need data while I was talking, I'd get a tablet with a data plan.
So the real choice is probably whether you want a phone that can handle simultaneous voice and data or a phone with decent battery life.
WHO IN THERE RIGHT MIND CAME UP WITH THIS IDEA, WE ARE NOT IN THE STONE AGE ANYMORE, WE STOP USING FLIP PHONES, (NO OFFENES TO WHO DOES) WE ALL NEED TO MULTI-TASK I DO IT EVER DAY WHILE I AM AT WORK, I AM A FIELD TECH SO I NEED MY VOICE AND DATA SIRVICE TO BE WORKING AT ALL TIME MOST OF THE TIME IN THE FEEL WE COMMNICATE WITH EMAILS, NOW I CAN'T GET AN EMAIL WHILE I AM ON THE PHONE SAD I AM SWITCHING. I HARDLY GET GOOD SIRVICE IN MY HOUSE, BUT I WAS A LOYAL COSTUMER TO SPRINT BUT NOT NO MORE THIS IS THE STREW THAT BROKE THE CAMELS BACK I AM A MULTI-TASKER AND THAT WILL NEVER CHANGE, SPRINT JUST SHOT THERESELF IN THE LEG SPARK THIS!! SPRINT CRIPPLED THE S5