I have had the 800 for two months.  The problem is the temperature control and thermometers don't work too well. Right now, the grill has been lit for about twenty minutes and set at 300 degrees.  According to the electronic thermometer it has never reached the set temp, always 10-15 degrees low, The built in thermometer is on the far left side and usually doesn't show the correct temp in the middle of the cooking area, off by as much as 30 degrees.  I have temp fluctuations of +- 10 degrees.  Also the meat thermometer will not register above 127 degrees and I have tried all four ports. Totally useless.  
Takes longer to come up to temp than advertised