Ultimate in FUN track/street bike?

We constantly read what is the fastsest and quickest lap times, but for most like me that love to ride/commute and enjoy the nirvana of track days, but have no desire to be the fastest on the track or ever compete we are lacking, compounded by little chance of test riding a new bike. Again, the emphasis is on fun not fast. At the same time being blown off the track on your light 250 by a liter bike is not tons of fun either. Been riding 45 years, 60 y/o and ride a '99 R6 with nice mods. Thinking of '12-'13 Touno, S1000RR, Daytona 675R. I'm 70/30 street/track and live in Mendocino Co. and my track is Thunderhill where a good time for me is 2:20.

Really appreciate the feedback!!  

Hard to know just what you are looking for, fun but not fast but not being blown off the track is somewhat contradictory.  For example, while the R6 is nimble one has to spin it, wring its neck, to go fast.  

Sounds like you want a nimble bike but with a broad big power band - liter bike, perhaps.  

Thanks for the reply, I've been leaning towards a liter bike as many like the S1000RR weigh less than 20# more than say the 675R or a typical 600. It seems like it may be the best of both worlds - reasonable light and nimble AND gobs of power. Over the years I've heard many track day guys say that the liter bikes are a real handful being heavy, and too powerful to control. I think the latest generation, again like the BMW S1000RR, are light, quick to turn and manageable with today's electronics.

Thoughts?

btw - this is an interesting forum, several hundred reads and one response.  

The 600 class fours even if we assume that they weigh more than a liter bike, will still be more nimble because they have smaller and lighter crankshafts, and that means they have less gyroscopic precession.  

The same applies for twins and singles.  For instance, all other things held equal, a 530cc KTM single will be more nimble than a 500cc transverse four, assuming that the single's crankshaft is lighter.  The diameter of the crankshaft can matter too.  Back in the hayday of the British singles, folks argued about the effect of crankshaft flywheel diameter, holding weight constant, on overall motorcycle handling.

My impression of the BMW you mention is that it is not built for ridabilty, rather for max power, so it's peaky.  I'd look at the new Kawasaki 1000 naked bike or what I ride, CBR1000RR.  I can't comment on the Kawasaki but I'm very pleased with the agility and mid range of the Honda; as for top end, unless you are on a big fast track, you won't give up much.  Now that I think on it; I haven't been "motored" yet on that thing and that includes several track days but I'm quick to admit that there are certainly higher HP bikes out there, just haven't had the pleasure of their company.  

All the motorcycle you mentioned are fun street bikes. Can't go wrong with any of them. Keith Code went from 600s to the BMW in his Super Bike School and has his accident rate go WAAAYYY down due to it's electronics so that is definitely something to consider. When you go to purchase you may be able to get a ride if you bring cash to the table. I have always given rides but only if they bring cash. I sell them the bike with a 30 minute buy back guarantee. Or we trade off if they come on a MC and we go for a ride together. My brother in law Mike has a LOT of dirt riding under his belt and also rides street. When his brother and I left him in the dust on a mountain ride one day he went to the California Super-bike School and rode the BMW. He said it took everything he had not to go buy one! He has been riding an FZ-1. Sept he is going to the advance Superbike school we will see if he can refrain once again from getting a BMW.