You can get “designer” ones with / without the convector fins on the back – on otherwise identical rads, just that one change makes a massive difference to the quoted output figures. Probably also need to check the fins are orientated correctly for vertical / horizontal installation.
We’ve got a load of Milano Windsor radiators in the house, replacing the very utilitarian square variety, some finned, some not, but also adding radiators where we’ve extended out back and up. Four out of eight are vertical. They work well but I’d recommend oversizing all of them. And because we added three radiators and a towel rail and because all the radiators contain more water, we’ve had to add an extra expansion vessel (a larger boiler may be fine). They really do look so much better, especially on coloured walls where you can see through them.