I had a Zilla, it was a monster both in terms of power and problems. They can be made to be reliable but it will take deep pockets. The times mine ran well it was amazing, like "Arm stretching Amazing" the rest of the time it was a problem. It comes down to what you want to use it for; it is big so it makes things sketchy on tight trails. For wide open areas nothing with touch it, 250r will not come close, Banshees will not come close, it is the King for a reason. Also parts are hard to find. Just my .02
85 ATC110 - The Greatest ATC of all time - (My First - new in 85)
83 FL250 - Odyssey w/420cc - SOLD
82 185s -10.25:1 piston, Full 200x upper, Goki Electric start - SOLD
84 200x - Auto-X - Weisco Hi-comp, Cam'd, Bassani'd, Westcoast swinger, -SOLD
82 200E Big Red -SOLD
85 ATC250ES Big Red - Snow Plow !