A properly broken-in engine and an oil change after 50K is going to be far more important than anything relating to oil after the break-in period. Every mechanic I talk to (who actually take apart engines on a regular basis) all mention a proper break in is far more important than brand of oil.
Speaking of breaking in engines, this is pretty much the one where every mechanic I know mentions the manufacturers recommendations are wrong (going easy on it). The only reason why you're told to go easy on it is for liability reasons (they dont want you taking a new car into the road and bagging on it). Going easy on your engine for the first couple thousand miles is one of the worst things you can do for engine break-in. Long story short, the first 50-100K's is the most important, and you need to run the engine through it's entire rev-range. Warm up the engine completely, and then take it onto a road or highway in 2nd or 3rd gear, and slowly and methodically run it through it's entire range with roll-ons.
I also ride sportbikes and I've seen the effects of a poorly broken in engine first hand. Bikes that are broken in on a Dyno or Track (read: properly) always end up making more HP (albeit single digits, not huge numbers here). I personally didn't believe this until I had it done myself on the last bike I purchased, and my friend who purchased the exact same bike didn't, and it showed on the dyno. Take it for what you will, but this is coming from mechanics who work and tune racebikes for professional racing teams. Mention "going easy" on an engine for the first couple thousand miles and they laugh.
Long story short, break-in and other things are far more important than oil brand.
More info here:
http://www.mototuneusa.com/break_in_secrets.htm