here's my take on these two sweet forks… i've got both:
08 Fox 36 Talas: actual weight w/ 8 inch steerer = 2.3kg/5.1lbs. i run this on a 6inch/30lb trail bike and it rocks. wicked high and low speed adjustability, good (but not great) bottom out (for the amount of travel), pretty linear feel, very good high speed/initial stoke dampening. coming from 8inch DC forks for DH/FR, this fork just doesn't have the travel and save-your-ass factor that a bigger fork does. it feels like a mini-DH fork and is awesome for smooth tranny boneyard/dirt jump type stuff but will make you work a lot more in hairy cypress-type riding. i have never done a day at whistler with this fork but i would imagine i'd feel much more beat up after 15 or so laps than with a bigger fork, unless of course u are just doing doubles all day.
08 66ATA - actual weight w/ 8inch steerer = 2.86kg/6.3lbs - only a hand full of rides so far but this fork is the full meal deal. using it on a 7inch FR bike and also tried on 8.5 inch DH rig. it takes the sketchy/ rutty/ crappy tranny moves just as good or better than an 8 inch DC fork. i can't imagine needing more fork than this for anything. it will cover your butt when you need it. awesome bottom out (PAR system) and buttery marz initial travel, stiff as hell, doesn't feel like an air fork. very different feel than linear fox travel - feels bottomless. actual travel is slightly less than 180 - somewhere around 170-175mm - close enough. wind down feature is sweet for pedaling up.
out of the two, for real freeriding the 66 is a better fork IMO at a reasonable 1lb weight penalty. perhaps the coil 36 would be a better comparison to the 66. at 6.3lbs actual weight it's very light for what it does - compare to dual crowns at 0.5 to 1lb heavier (excl. boxxer WC).