Bravissimo for bikinis that fit. That’s all I have to say on the matter.

Apart from that I would just about take 20 minutes in an ill-fitting bra over 20 miles on the wrong saddle. It’s close though.
Both can be excruciating after about 5 mins...

And at least with a saddle you don't have to deal with the fact that they're falling out of the bottom, or out of the top, the straps keep migrating, or you feel like you've got ever-tightening ratchet straps on your shoulders that leave you with deep gouges and a splitting headache...
Will definitely keep Bravissimo in mind next time I go to Cambridge.

I'm not a bikini girl, but I could really use something nice that's not a sports bra.

The Lonsdale racer back ones are a good fit, but they're very, how shall I put it, utilitarian.