1 – When it says preheat, for the fuller (non-stick) grill – it means at “full power”, not the “keep-warm” setting.
2 – It recommends preheat for 6 minutes, I find 10 minutes works best.
3 – When you preheat – for the 1st time – it seems that you open the “gates of Hell” on your kitchen…yes you can feel the heat! Just step away for 10 minutes. Make sure you do not place it under any counters – it needs a very open space – For the “lighter” grill there’s no need to preheat.
4 – It is very hard to see if your meats/poultry are cooking properly, because of the infrared light (my 1st try was at night…) so use a high-power white light, or cook during the day – that way you can see the “doneness” better.
5 – It is smokeless! Truly! (I’m very pleased by this…) though, I would suggest opening up some windows to get rid of the BBQ smell – you’ll notice next day (believe me!) If you can’t open up the windows, turn on the range smoke extractor for your stove! And if you have some air filters, turn them on – that way you avoid any lingering smells next day (it’ll be noisy, but just for 15 – 20 minutes…)
6 – The thicker the cut of meat, poultry, fish, etc. the longer it needs to be on the grill to achieve a well done consistency. Personally I do not like too much pink on my steaks, so I keep them on longer. Today I did some Bubba burgers, and had them on the grill for 5 minutes each side – they turned out perfect.
7 – The “keep warm” function works pretty good – I had one of my burgers on for about 15 minutes and it did not dry out.
8 – Clean up – make sure the grill is fully cooled down to start clean up – this takes about half hour of cooling (depending on your ambient temperature.) Run the (separate, detachable) grills under some warm/hot water (I prefer as hot as possible) and get a good, sturdy nylon bristle brush with lots of dish washing soap and run it good through the grill – make sure to go in between to get all the drippings and fat that runs down from the meats. Depending on the “fattiness” of the meats that you cook on the grill, some splatter will occur into the internal walls of the unit itself, I find it that if you scrub it with a sponge (with warm/hot water and dish washing soap) and just wipe it down – it’ll make for a better/cleaner use the next time around – remember, the unit cannot/should not be dipped in water (as it would ruin the electrical components.)

I hope my “observations” helped – and Happy 4th of July!