I have had the High-Que fire grate for about 6 months now. I love it. It gets the temp to blazing temps fast and also does great for low and slows (I see no difference between the original fire grate and the High-Que one during low and slows). I have done numerous low and slows with the High-Que and see no difference in the amount of lump I used. Maintaining constant temps with it was dead on. My last low and slow was last weekend doing 2 pork butts and I smoked them for 18 hours at 235-240 grid and still had a lot of lump left (I filled the lump to a little over the fire ring and had about 1/3 of the lump left after 18 hours).
The High-Que blows the original one out of the water for high temps and getting high temps fast. No comparison. I also see no difference with the amount of lump I use in high temps either. It is the same for both. The High-Que was delivered fast and is built to last. Very high quality.
Last night I left my Egg going full throttle and forgot about it for 30 mins (was watching a game). I came back and the Egg was at about 1,300 degrees. I was doing a TRex steak and put the steaks on for 60 secs (I usually do it for 90 secs a side depending on thickness and temp) a side using my GrillGrates (love the GrillGrates-highly recommend these also) because the temp was so high. Steaks (flat iron steak--I love flat irons) turned out great (used Dizzy Pig's Cow Lick rub and cooked to medium rare). My point is the High-Que did a great job and performed well at those high temps.
Naked Whiz's review on it was spot on and I can also highly recommend it.