well, the fillers don't count, but he did spend half a year getting back together (or at least, we saw Sakura's trainning in three months' jumps, so we know he hasn't left the village at those six months). still that leaves him 30 months of trainning with the best 'good' ninja around.
now, i don't remember the Manga after the time jump so well, so feel free to correct me, but when he came back we saw Naruto being able to..
1. Move around with his shadow clones in midair.
2. Block Chiyo from charging at Kakashi.
3. Punch deidara in the face and go wild on his ass.
4. control the Kyuubi up to the 3rd tail.
now, 1-3 is pure taijutsu trainning, it's normal leveling up. the Kyuubi power seems to be the real base of the trainning, but apparntly, his control over the first tails was also lacking (he lost his calm at the deidara fight).
about the what stoopider asked, I believe that the fighting abilities come from the demon itself, since Naruto's fighting moves at the kyuubi stage was defintally not something he could train (though, sending chackra claws might be a variation of chackra form manipulation), there's no way he could train to shoot energy beams from his mouth or to realese himself in chackra form and punch Orochimaru...
So basically, whenever people train offscreen for three years, it's not nearly effective as an onscreen trainning arc.