He was a fine lead guitarist as well.
"Fine" is perhaps overstating it a little!
I think you can hear in that vid very clearly that he is not really comfortable (or enjoying) playing lead, bit angular and not fluid at all. Leadon's solo at the end is in another league. It's the first time I actually see Glenn playing a solo with the Eagles, I now understand why he was so quick to become the "rhythm guitarist only" (and later on: "acoustic rhythm guitarist only") once Felder and later on Walsh, both of them fine lead guitarists (not that Leadon wasn't), had joined. It takes a great man to recognize his own limits.
That's not knocking Glenn, you can pave the roads with fluidly-playing, non-angular guitarists, but Frey's vocal and songwriting talent is rare. And if those backing vocals are the original live ones (and they sound in places un-perfect enough to be untampered with even though the Eagles spent weeks studio-honing the backing vocals on later live recordings***), then I'm even more impressed than I generally am of the feathered ones.
Worthy opening act of that British headliner at that concert ...
Timothy B. Schmit, when asked by a German musician mag if The Eagles backing vocals on live DVDs etc are "really live", replied smilingly:
"Let's put it this way: Don (Henley) is very particular about the backing vocals and will do anything to make the end result sound right for the listener."