This telling of the Don Juan story, set in Soho and featuring David Tennant and Adrian Scarborough is riotously funny. The back and forth between the two leads is beautifully well done, and easily the best aspect of the performance. Occasionally makes you wonder if it could just be done as a two-hander. That includes the slightly unexpected musical number.
I rate Scarborough a little above Tennant, mainly because Tennant tends to overplay it a little. That is his style in general, but it can get a little grating. Scarborough on the other hand hits every comedic point perfectly. That's verbally, mind you. Tennant has some wonderful moments of physical comedy.
Supporting characters are fairly decent, though then oddly tend to feel a little RSC, in what generally feels more like a farce. This is mainly an issue with "poor little wifey's" family, as their serious counterplot to the main silliness doesn't quite mesh.
The other aspect that doesn't mesh well is the soliloquising. Tennant gets a couple of speeches on the vagaries of modern life. Part of this seems to be the self-destruction of Don Juan's mind, but it also has some rather hamfisted topical politics, with some very easy point scoring to get the audience to cheer along. Now maybe Patrick Marber is sat laughing at the audience, as they cheer along with Don Juan's hypocrisy, but it feels too earnest for that. And the final problem with topical references is that they don't stay topical. Sure, laughing at Trump's wig and mental state was funny last year, but now we've had six months of it, it's just not as funny. Topical references need to stay topical.
Putting aside those thoughts though, which loom large on the page but don't really make up much in the theatre, it is an excellent example of the farce.