Decent (and nostalgic) period piece, easily standing on its own in a company of Pufnstuf and Lions, imho. Not for the people who cringe at classical music though. =) All these visiting muppets looking familiar make it at times seem like another Muppet Show backstage, twice removed. One very special thing to watch for is truly amazing expressiveness Richard Hunt gives to his character.
Also -- shows how much depends on writing... and on everything else. Getting exactly right crowd together means a LOT -- Speaking of TMS, it's so not often that the stars just click in place and you get Jack Burns and Jerry Juhl on writing, the whole classic team performing, and yet another classic team designing the muppets, exactly right spirit and tone of creativity at exactly right period when society was ready for it, and Sir Lew Grade getting on board just in time to support it all... and the very right person very directly involved in the center of everything! So while we all keep hoping for another such cosmic moment to happen again, i guess, it should not prevent us from appreciating how rare and delicate and easily disrupted the whole Muppet magic really is.