Yeh I'll second that. Used 600w hid for years. Fell for all the adverts for led grow lights. Spent nearly £300 on one an sold my hid. VERY disappointing results. Slow growth small plants, small buds. Sold it on eBay after one grow an bought another hid. Moral of the story, stick to what we all no works best.
Just as a side as well, google 'smart growlamps'. now this is one light I would prefer over my hid although a little on the expensive side at the moment I'm sure they will start coming down a bit soon. Induction lighting is looking to be the way of the future grower. No heat, half the running costs, and Very good results.