I'll start by saying I majorly compromised on fit in order to own this bra, because it's lovely. In theory I'd need a 26K for proper fit of this bra. I bought a 28J, the right cup is too small but manageable due to stretch lace and I'm wearing the bra on its tightest hooks. For me this is a frustrating issue because while I've accepted that Bravissimo is never going to cater to a 26 band, it's endlessly frustrating that everything stops at a J cup in a 28 band.
The bra itself is mostly comfortable, I like to wear it with my deep V neck dresses because the centre gore is the lowest of all my bras. The underwire on the 28 band is much too wide (again a common problem with Bravissimo bras in a small band) I do not have breast tissue half way around my back, and yet for some reason the underwire goes all the way back, this does lead to some uncomfortable digging in after a day of wear. I've also found the straps are much too long - in order to have the straps tightened enough I have to have the slider sitting in my collar bone, which hurts, so I have to leave the straps too loose. I'll note that I'm 5ft5, so it's not like this is happening because I'm particularly short.
Despite all of these issues I still wear a Millie on most days, because I love the shape and it actually makes my boobs look a little smaller. It's a bit bouncier than my Lola, but the stretch lace is obviously going to do this.