The Stage has a favourable review of both the production and Alex:
"The part of Garry Essendine - a successful romantic comedy actor who attracts adoring young women and men in Noel Cowards’ 1942 play - could have been written for Alex Jennings. He gets the over-acting, outrage and moodiness, underpinned by the usual artistic angst, insecurity and querulousness, perfectly. The masterly Jennings can also get a laugh merely by lifting an eyebrow and turns quizzicality into an art form. Essendine is a huge Hamlet-sized role, rarely off-stage but, apparently inexhaustible, Jennings is as riveting in the final minutes as at his first appearance."
Full review: The Stage