"If your son son runs a 6.6 60yd which is pretty good (but not elite)"
Fenway, we seldom disagree, but in my experience the Bell curve is pretty steep on its sides -- meaning, a 6.6 runner is pretty darned elite. Provided he really runs 6.6, consistently, as opposed to that being a helicopter parent's fictional account.
Let's put it this way. We'd all like to run 7.0, and that seems to be the turning point in a lot of minds, but the reality is most of us can only dream of being that fast. 7.0 is a number you need to get serious consideration at many positions, but there are still plenty of slower guys getting recruited. (Some, however, are taken on as projects, and show tremendous improvement once their college coaches introduce them to real speed coaches for the first times in their lives.)
I've seen 6.8-6.9 guys who read pitchers well and get great jumps, and they pretty much steal at will. I've seen 6.7-6.8 guys who don't and they are safe most of the time but will get caught on their bad jumps. A 6.6 guy, with a little instruction, should be safe every time the ump isn't blind.
We do all we can to look to recruit speed on our team. So far, as we start our 6th cycle, we've had one guy who peaked at 6.3 and consistently ran 6.4-6.5; he could not be thrown out stealing or bunting, and he's now playing in the ACC. We had one guy who peaked at 6.6, more typically was 6.8, he's an outfielder in the Big South. We had one guy who was 6.75, very aggressive but sometimes sloppy with technique. He was unstoppable in HS, got caught occasionally in travel. He was forced to improve in college, now runs 6.3 and is unstoppable (also Big South). We've had only one other guy with 6.6 speed, everyone wanted him, and he's now at JuCo because of the need to get his academic numbers up.
I've seen only 1 other guy out of probably over 1,000 who've tried out with us over the years who were even in that range. So to me, 6.6 is "elite."
Not trying to be picky, I just don't want someone who runs a 6.9 or something to feel discouraged.
I would also add that sometimes these numbers are one indicator that a kid is indeed highly athletic. Most of our super fast guys were guys with very little body fat and a lot of other athleticism evident. If there's a moral to be found it is this: Get yourself into top physical condition. If you haven't done this, everyone who sees you knows you aren't working as hard as you could, and that is probably the negative that stands out more so than any stopwatch number.