For heat output check the delta reported for the BTUs.
I found numerous ‘designer’ radiators reported a 60C delta T while some reported both 50C and 60C delta T.
Anyone used ukradiators?
I think a few guys I know have used them. I haven't heard anything which usually means it's all fine, if they were crap they'd make a noise.
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.
Just ordered 3 NG ones off Amazon. Hope I don't regret it. They had the sizes I want in stock.