As for how these numbers compare to how it looks in real life -- I'd say my two fastest players are two of the fastest players we've played, so I don't think 2.68 overly exaggerates their speed. Our players in the 3.00+ are what i would consider average to slow. Put another way, I think if I timed using the bunt/soft toss, I'd add about .20 to their times.
I understand your logic of "as long as your are consistent" you can measure improvement, but I would not give out these numbers to others. Here is a chart showing the times of the Olympic softball team - including Natasha Watley.
Home to 1st (righty) Home to 1st (lefty) 2nd to Home Home to Home
Slow Above 3.0 Above 3.0 Above 6sec Above 12.5sec
Average 3.0 sec 2.7 - 2.8 5.75 sec 11.50 - 12.00
Good 2.8 sec 2.5 - 2.6 5.3 - 5.5 11.00 - 11.3
Great 2.6 sec 2.3 - 2.4* 5.2 or lower 10.8 or lower
* Natasha Watley - US Olympic Team
Softball Excellence