Capos..yeah, I can see where the lead singer might want one, for easy chord positions to match his vocal range, but for the lead guitar it doesn't make too much sense to me.  I think for lead runs, where there is a rhythmn guitar a capo isn't necessary and the guitar sounds better without one, unless...maybe he's using an altered tuning, which might be the reason he's also capoed.   Capo certainly does make some things easy, but it's a real nightmare for tuning, since it throws the intonation way off.  One of my personal favs is using it for songs written in C using the capo at 5th fret and playing the thing in G shape.   And in Bluegrass, most players just play everything possible in G shape and slide the capo up and down, so they can use the open strings on the single note lines.  Yeeeehaww!