I talked about it in the gameday thread a little. The advantages are only there if:
(1) you have superior guys on the outside who can make plays (or if the plays are "given" b/c the defense plays off/zone)
(2) the defense sticks to its assignments and doesn't attack the gaps.
It's not seen more because you're likely to get your QB killed and plays blown up sooner or later when the defense adjusts, attacks the A and B gaps with violence, and presses outside. Everything gets thrown out of rhythm.
This isn't a "new" thing or something that lacks "film" (or history), which is something that was weird that the announcers alluded to. The 3' to 5' splits were historically used by wing and option teams trying to get advantages on their angles, make passing lanes a little clearer, making the zone reads easier for QBs and to mitigate the edge pass rush.
In the HS game, I've seen defenses take the very practical approach of slanting hard and/or placing LBs inside to blitz A gaps. In college, take a look at what teams try to do against Leach's Texas Tech teams that sometimes had very wide splits.What that leaves are some matchups in the secondary. However, I'd prefer to take my chances that a QB can consistently find and accurately hit his receiver (who's being covered man to man) while getting assaulted by defenders flying up the middle.