The copy T6's are like the Magicshines which are a copy of major manufacturers lights. The copy copies use a different size connector from the magicshines, but you can get around that with an adapter if you want to use ms batteries or light units. The issue is these really cheap ones use really cheap batteries, you might be ok, you might not. Probably have a higher fail rate than magicshine, and they aren't perfect by a long shot.
Magicshine has got better, and the batteries have improved.
£26 isn't much for a very bright light. Just remember these aren't that good on road as they can dazzle drivers, i put tape over the top of my MS to reduce that when its on the road sections, and angle it down, but it's mainly for off road.