As i said before. So Random! is a good choice of show for a Muppet to guest on since it's a sketch-comedy/variety show and right up the Muppets' alley.
But it's just too bad the show itself is so unfunny. Demi Lovato leaving Sonny With a Chance essentially forcing the show to change its format to actually becoming the show within the show it was was the worst thing to happen to it...a full episode of really bad amateurish sketch comedy is pretty painful and i fully blame the writing/production since there are actually some really good talents on there (i really like Tiffani Thornton but she's totally held back here and if given the chance to do something else/better i can see her becoming pretty big)
So of course the biggest problem with the episode were the non-Piggy sketches. Since i don't regularly watch So Random! i don't know how much screen time their guest stars usually get but with the plotline involving the cast wanting Piggy to appear in their sketches, Piggy was a bit wasted because she only got to appear in the closing sketch. The show could have worked around this by either (a) showing the cast members presenting their pitches to Piggy leading into a "fantasy" of what the sketch might look like with her involvement or (b) included some other Muppets even as cameos...this would have been the ideal opportunity to have Statler and Waldorf snark on the various sketches.
But still, non-Muppet parts aside, i enjoyed it and it's great exposure for Piggy. Though i do have to say in just two minutes, Piggy's appearance on Take Two with Phineas and Ferb put her 21 minute So Random episode to shame.
Interesting to note the credits just listed her as Miss Piggy with no acknowledgement of the man underneath the curtain (ie "Piggy's Personal Assistant" or anything like that)