Lots of emotion and exertion in those photos Dean, well done!
A good demonstration of a need for bursts is any sport that doesn't necessarily have a predictable peak of action, like you show here. Same goes for Wildlife where in 80% of cases one has no idea where and when a peak of action will occur!
Thanks so much. I used to shoot crew - just wait for the boats to come by and shoot in burst for 30 seconds! Ultimate is much more challenging - it just keeps moving. I alternate between following the disc and then just following my son or some other player. I have plenty of memory cards and accept the fact that I will shoot 1,000 frames in a tournament to get 30 good ones. One thing I am always aware of is that when a player gets the disc they don't move so I use that moment to pre-focus then shoot bursts as they fake and dodge and try to catch the disc just as it leaves their hands. With long throws it easier to follow the disc - but I keep an eye out for the intended receiver and pivot to them as soon as I see where its going. I shoot a little wide and crop in post. It will definitely increases the keeper count.
Shooting Puffins and Gannets from a bobbing trawler in a heavy swell in the Arctic Ocean with a D700 and long lens 2 years ago demonstrated just how good the D700 is for fast action work. I am doubtful that the D800 would have delivered in that instance, although the D7000 would have but with reduced IQ.
If one can get closer the D700 makes a great action camera.
Nice shots, I've been using my D700 with same set up for my sons' spring flag football games, and it has served me well in the gym during basketball season over the winter. I've been toying with the idea of getting a D4 or D800 but my current set-up works great, I've determined to hold tight with what I've got...and it's the first-release 70-200 VR with mild vignetting at times. I'll be curious to hear how you like your D800, I'm thinking of saving my pennies for the D4 by end of year.