I have an 05 750 that I now use as a track bike. I started off by going 16/44 when i rode it on the street. Some of the books will show the bike coming with a 17/42 set up, mine had the 17/43, which I found out when installing the new one. My opinion is that you if you are going to change gearing, go down 1 up front, then fine tune it with the rear to get it where you want it. The rear is much easier to change and makes smaller changes. To large of a rear sprocket can limit future options in gearing because you will need a longer chain just to get it on the bike. If you try to go down on the rear after that you will probably run out of adjustment.
I did a track day on Memorial Day at Streets of Willow and i started with a 16/44. Good pull, but i found myself only using 2nd and 3rd gear, 4th at the top of the straight. It was a little hard to get a good charged out of the corners and keep up with the litre bikes. At lunch I switched it out to a 16/46. This worked outstanding! It gave me a greater range of use of my gearbox, excellent charge out of the corners, kept the revs up and allowed me to pull the litre bikes up the straight.
I picked up an extra cush drive, the part of the rear wheel the sprocket mounts to, off of e-bay to mount an extra sprocket to so i can make quick changes at the track. That along with a set of Gilles chain adjusters was key to quick and easy mods during lunch.
With a 16/46*525 my axel sits almost all the way forward. I can then slide it back and still have enough room to adjust for a 43 or 42.
I have an excellent Excel spreadsheet that was passed on to me that breaks all this down. Input in your tranny ratios, tire size, power band, redline, front and rear sprockets and PRESTO! It will tell top speed in each gear, final ratios, shift up and down points and all kinds of stuff. If someone will tellme how to make it available to all of you i would like to, it is a great tool. Or i will send it to someone who knows how to post it.
Sorry for the long winded reply, but this is something i have spent some time on lately.