This episode was full of very cliche and predictable plot threads. I mean, that often happens with this show, but for whatever reason I really noticed it this time. Let's jump in.
Cons:
Bernadette and Howard's plot line was all about Stuart finally moving out of the house. He leaves without much ceremony, and while Bernadette and Howard are discussing what to do with his now-vacant room, they reminisce about him, talking about him as if he were their child who has moved out of the house. They realize they miss him. This is just... well, it's clearly part of the half-assed story line about Bernadette and Howard having kids some day, but it didn't pack a punch, didn't get a lot of laughs, and felt totally obvious from the second Stuart said he was moving out.
Similarly, Leonard and Penny's plot line offered no real surprises. Penny has had a hard time getting in to see a psychiatrist about a new drug her company is selling, so she gets Leonard to sign up for a session with the woman so he can pretend to be a patient, and lay the groundwork for Penny making her sale. Inevitably, Leonard ends up getting a lot of meaning out of his session, as he talks about his relationship with his mother, his problems with Sheldon, his marriage to Penny, etc. When Penny comes in to do her sales presentation, the psychiatrist ends up giving her an impromptu session as well, where they begin to unpack Penny's issues. People who don't think they need psychiatrists actually needing to talk to somebody is a tired cliche and most sitcoms have used it at some point or another. Off the top of my head, I can think of an episode in Scrubs and an entire plot thread from How I Met Your Mother that employ this same setup.