Only used the prototype, but it was marginally better than the Crosscountry Class 220s (which is surely the benchmark for crap cycle provision) on account of being able to get at the space from the side, rather than just the end. Usual problems of hanging long bikes, heavy bikes, bikes with fat tyres and wide handlebars apply. If they've come up with a way to stop, say, a 40mm Marathon from fitting, they deserve an extra slow clap.
The two-hanging-bikes-space unit is modular (it could be replaced by an inaccessible toilet or catering trolley dock module), so the exact number and position of spaces will be TOC specific. I believe this is also the reason why they haven't been marked on the outside of the train.