I think we're all curious about the radios - without proper teardowns, all we have are our own anecdotal reports so far, and without a release, we don't even have that for the SGS3.
So far, our concensus is that the 3G and wifi radios themselves in the LTEvo are very good (despite there being a software bug affecting some wifi users). Throughput on both 3G and wifi is far better than what I had on my Evo 3D, and we know from lab reports that the LTEvo 3G radio has only 1 dBm less sensitivity than in the original Evo. All LTEvo GPS have been great that I've seen, and I've seen too few LTE reports to feel comfortable saying anything on that one way or the other.
The whole S4 thing isn't a big deal.
To make a phone call, you need software (done deal), a processor (to run the software), various modems to connect various radio transceiver chips and antennas connected to the radio chips.
The S4 processor includes what Qualcomm (the maker) calls a World Modem - it's programmable to serve any cellular radio standard in the world right now.
So an S4 on a 3G/4G phone is too good of a deal to pass up - fewer chips, less power draw, less manufacturing complexity and costs, higher reliability.
Meanwhile, chip fans will debate the merits of Samsung quad core vs the Qualcomm dual core, but that's part of the Android landscape, that will never change.
Bottom line, you're well served having an S4 chip for any USA phone when you look at the big picture and not one synthetic benchmark vs another synthetic benchmark, because benchmarks create more questions than they answer, tbh.
