As the title suggests, Rick Spleen is a comedian who has taken to doing corporate jobs to pay the bills. His writing partner Marty doesn't really help by giving him lines destined to stink up the room but mostly it is just day-to-day life that gets Rick down. Unable to accept the little things about society that we all have to deal with, Rick's days are filled minor irritations and obstacles.
From the opening few scenes of the first episode you can see where Dee has drawn his influence from as others have said it is very much Curb Your Enthusiasm in style. Of course this is an unfortunate comparison because in fairness Dee has been doing this sort of "weary at minor issues" thing for years and those that like him will find this series to be more or less what he does well. The writing is good and the scenarios are well structured and funny. In some way the scripted approach works better than Curb because it isn't allowed to flow and thus is closer to what most sitcom viewers would expect from it. However it is impossible to avoid the comparisons with Curb and viewers that love that series will perhaps not allow themselves to find any value in this, which is a shame because it is actually pretty funny.
Of course it helps to like Dee but, speaking as someone not too keen on him, I still enjoyed it because he wasn't overly miserable and his material was mostly funny. At times his delivery is a bit heavy but this is not too often. Cassidy works well alongside him but her "supportive sensible wife" thing is again a bit too close to the Curb dynamics for comfort. Power is a wise addition and lifts the material to a degree, while Gardner is a good character albeit used simply.
Overall then an enjoyably acerbic and impatient comedy that will appeal to fans of Jack Dee but should also have a wider audience given how very funny it can be. Comparing it to Curb tends to lean towards criticism but for me personally I just tried to ignore this and focus on the material, which is mostly well written, well delivered and has sufficient laughs to be worth a look.