I like this stuff. I like it when it's a sharp witted but generally sweet young thing married a wealthy and hardened older man in actual Heyer novels. I like it when it is Harriet Vane angsting around Lord Peter and Bunter. I like it when it is set on Liad and involves Delms instead of Dukes. I really got a kick out of Cordelia and Aral and blah blah bleeping blah.
It has recently occurred to me that the billionaire subgenre of contemporary romance, which I neither love nor read with any frequency, is pretty closely related to these books. It's just more rich guys without the titles, but a lot of the set pieces are virtually identical (right down to the, hey, you shouldn't have gone out without telling people bit or the forced shopping expeditions or the slow burning battles between household staff and Young Wife/Lover/Wtf).
This leads me to suspect that I've been harshing on the billionaire subgenre somewhat unfairly. Really, it is not like the space opera or regency stuff was particularly realistic, so why do I expect the billionaire's method of acquiring great wealth and/or deploying it make sense? OTOH, a bunch of the billionaire subgenre has apparently been quite 50 Shades in terms of dude with the bucks is into BDSM (and angsty, but there is no way I can love Sayers' Lord Peter and complain about angsty because, hypocrisy).
Those are the remarks: I have realism issues with how these characters get and deploy their wealth, and I have a lot of motivational issues associated with why the characters find each other interesting. Here's the question: is there a list of set pieces that you, as a reader of billionaire romance, would be disappointed if absent from a billionaire romance? I think the forced shopping expedition is so frequent it must on some level be mandatory. But what else is required? Is there a standard romance novel trope that is inherently incompatible with the billionaire romance? I've put many of these questions to my sister already, but I'd love to hear from anyone with an (at least minimally informed) opinion.
ETA: I should add that part of my interest derives from Ilona Andrews layering the billionaire/dynastic familiy trope onto their new series.