I can see my opinion might go against the grain here (it seems to often!), but I think that the latest episode was not as good as the last, and is nowhere near the best, perhaps almost one of the worst. I'll tell you why.
I have always enjoyed the IT crowd because you have great comedy derived from a lot of normal situations, but with the slightly eccentric characters. This usually results in them walking blindly into a difficult situation as a result of their slightly alternative take on their world. This latest episode instead gave us rather normal characters but forced into a crazy situation (more namely the story following Moss, the Roy window story was classic Linehan but still not great, I'll get onto that). The introduction of the Countdown club I found very strange, and the sections with 'minus 1' were at some points almost cringeworthy for me, rather than flat out amusing. This still delivered some great lines from Moss, but they felt a lot more forced than we're used to.
The Roy story in the latest episode was enjoyable. We get to watch him stumble around in his own awkwardness and ultimately end up looking stupid and causing the wrong impression. The only thing that ruined it was the terrible joke at the very end of the episode. It felt like the whole thing had built up to that and it was a disappointment when it came, very cheesy. I prefer something more subtle, which is how the previous series have presented a lot of the best short jokes like that.
The other strange thing about this episode was the Jen story. It didn't really go anywhere useful or particularly amusing, and rather disappointingly it played no part in the other stories of the episode. Graham Linehan is usually the master at weaving in all the plots at the end to come together in an extremely amusing and sometimes unexpected climax. The end was instead a disappointment for me and not as clever as we should expect.
With all that said however, even just on that episode, it's still one of the best comedies on TV, without a doubt. I eagerly anticipate the rest of the series!