Did you have the 12/45 gearing when i rode your bike at Cahuilla?
I just recently bought a 52 tooth rear, and even the 1 tooth smaller sprocket in the rear the difference in feel of the bike was noticeable. Personally, I'm used to the snap of the stock gearing. In supercross, I think the lower FDR hurt me a little - I would have preferred more snap.
I rode the main track at Pala yesterday and the 12/52 seemed ok. On faster tracks i can see the advantage of sliding the power curve into the higher mph range.
I have a 13 and 14 tooth front sprocket i'd like to try on faster tracks. Stock FDR is 4.42. 13/52 will leave me with a 4.0 final drive. I think that may be the sweet spot for faster track. I think a 14/52 setup for motocross will be too low of a FDR, although it matches my race number
(3.71)