I still think Ummagumma is the worst album made by a good band. Only Gilmour's tracks are good ("The narrow way", and even then the second one has a bunch of random noise near the end. The rest goes from mediocre ("Grantchester Meadows) to unlistenable ("Several species of small furry animals gathered together in a cave and grooving with a pict" and "The grand vizier's garden party"). The first disc is also unappealing to me because I don't like Barrett's era at all, but the second one is pure trash except for Gilmour's compositions.
At least they got their act together and released Atom Heart Mother afterwards.