This Friday's episode was above average, I thought. In my opinion, probably one of the best ones in the show's history. It felt different and slightly fresher on a number of levels. Aesthetically, Robert Lindsay was wearing a black leather jacket (that sounds trivial and irrelevant, but it made a change from brown suede). Plot-wise, having Ben and Susan separate felt like a big step (separating being a serious thing to do, after all).
Also, right from the start, all the actors were on the button, from a dowey-eyed Michael shifting into the kitchen with the 'no, you hang up first' lines to Roger hastily running-then confidently strutting to the door for his date.
Having Ben gate-crash the dinner date was a good gag too - even if it wasn't original. And later, getting Ben and Susan out of the house and to the anniversary party also felt like it was adding more to it.
Roger falling downstairs with the mattress on top of him was a recycled gag as the same thing happened to Ben in Series 1, but having them on the stairs like that and glimpsing the fourth wall (the crew would've filmed it before or after the audience arrived) was another example of the production pushing harder than usual.
Or maybe I'm just blind-sighted by the virtually unwatchable episodes we've had recently.