04-12-2012 07:44 PM - edited 04-12-2012 07:45 PM
If you're with a carrier whose network is 4G, then both phones will support it. Keep in mind that one network's 4G is another's 3G+ while another network will label those speeds only 3G. Something really has to be done to find a common definition of 4G.
Incidentally, my 9860 shows H+ (for HSPA+), and it's 4G by my carrier's definition.
I hope that clears things up for you.
04-12-2012 07:59 PM - edited 04-12-2012 08:00 PM
Yes, it depends on your carrier. Think of your phone as a super-fast PC and your internet comes to you by dial-up modem. Your phone is up to par but if the network isn't delivering to its full potential, your phone won't be much quicker than 3G.
I can tell you firsthand that my carrier supports 4G (or very fast 3G+ if you will) and I see a difference.
P.S. To fully answer your question, if your phone is showing 4G or H+, you're good. You'll get some pretty amazing speeds.