I enjoy Phryne as a general proposition, but I find myself saying with almost every book (at least later in the series) that it’s not a favourite and I wouldn’t particularly recommend it on its own. If you like Phryne, it’s more of her usual, with daringness, nice clothes, some good food and a sexy man. It fits the formula and at least this one introduces her sister as an actual character, with interests and problems of her own. It’s all the usual glitz and glamour and peril you expect from Phryne, and nothing particularly surprising, moving or suspenseful. You know she’s going to come out okay in the end.
Which all sounds like damning with faint praise, which isn’t quite what I mean either. If you enjoy Phryne, it’s fine. It’s just not one that stands out to me, except maybe for some of Lin Chung’s interactions with his extended family, which make me laugh (though they are perhaps a tad stereotyped, as well).