Some 07's had a noisy clutch, Yamaha was installing a new clutch basket for people who complained while under warranty. Yamaha said the noise did not affect the performance of the clutch. (this is the way I understand it but I was not affected by it in 08)
Valve adjustments (valve checks) in earlier models were suggested every 4,000 miles. I understand part of EPA requirements until they knew more info on the new engine.
I have an 08, at 11,000 miles I have not done the valves yet simply because in the newer bikes (I think 2010 and later) the owners manual was changed to every 16,000 miles for a valve check. After reading these forums that seems to be holding true no matter the year.
All the above is on my understanding of reading the forums, except I did verify the newer bikes owners manuals call for 16,000 mile checks. I also checked the part numbers of the entire valve train and associated parts and they are the same part numbers, no matter what year. I have no reason to believe I need to check the valves until what the new owners manual says. This is my own interpretation, based on MANY comments by others who have done their own checks, maybe some one else can offer more.
Engine noise on most bikes, you will hear more valve clatter on bikes without hydraulic lifters and the way I understand it, you should hear some.