Second to the plot? Where's Maggie? Marge wanting to be cool?
All rubbish.
The Simpsons has never been about continuity or logic-driven plots, and I don't know why some people pretend they do. In one of the older episodes, Homer survived falling down a canyon. Twice! The Simpsons has always had an outlandish element.
That writes off the first two criticisms.
As for the third, this episode has nothing to do with Marge 'wanting to be cool'. It was about her wanting a break from her stressful life as the mother of a hell raiser, a gifted child and a baby. Marge isn't a robot. She loves her kids. Yes. She wants to do her best for them. Yes. She's an inhuman washing and cooking machine that never tires. No!
This is far from the first time we've seen Marge be a normal person. Someone who enjoys a bit of time off. We've seen her appreciate a spa day with Homer in one of the older episodes, for example.
Third criticism done and dusted.
As for the episode in general, it was a pretty fun one. The chase sequence at the mid-way point was creatively executed, and there were some good jokes sprinkled throughout.
7.5/10, rounded up.