I have the Halfords cheapy (£34 IIRC), I use it with a light touch and Autoglym products and am very pleased with it; not too abrasive or too fast so doesn’t eat into the paintwork much. Doesn’t take any less time to clean/polish the car but the shine is deeper.
Good long lead too so moving around the car without dragging the extension lead with it helps.
All in all, personally, I’d say you’ll do well to beat it on price.