I rode a friend's 380 CZ at the event a couple weekends ago. The area was hammered with storms for a couple weeks beforehand and there were some very muddy spots (especially in the woods for the cross-country on Friday) but wow, what a cool track. If the event is held again and you get a chance to make the trip to the USA for it I recommend you do so.
Some of the "Legends of MX" that were on hand were Brad Lackey, Dan LaPorte, John DeSoto, Tony DiStefano, Barry Higgins, Gary Bailey, John and Jack Penton, and Ron Lachien.
http://kgfphotos.smugmug.com/2013MXandEnduroeventsThere are three galleries of photos (not mine) from the Unadilla races on that page.
Here's the Google aerial view of the track.
http://tinyurl.com/km6sdjkIt is ridden anti-clockwise. At least one major extra turn was added that doesn't show on the image. Ignoring elevation changes Google measures it at about 1.3 miles, so I'd not be surprised to find it a good 1.4-1.5 miles per lap.
There were a lot of flooded fields in the area. There were plenty of muddy sections that formed deep ruts, and riding those with confidence was above my low skill level. The first set of races on Saturday were pretty ugly (for me) in many spots but they groomed the track during the break and it was was much improved for the second set, though there were still spots where I ended up slowing and/or falling down. The track owners did the very best they could with the spots that lacked drainage but it was an uphill battle after all the rain.
I survived without injury (though my pal broke his ankle), I had a good time, enjoyed seeing my friends, and was not always last.
In fact, in the first race I got a good start (I've usually been pretty good at that) and I had the lead for a corner or two before the faster people caught up and passed me. I'll take what small bit of glory I can get.
cheers,
Michael
