FP, I'm a very newly converted "rotational" believer for FP, but I would like to make a couple points.
One, Ichiro does not swing like the average MLB batter. The story is that he "can" and does swing rotational occasionally in workouts, but in games he is definitely a linear hitter. With his speed, all he is trying to do is make contact, preferable to the left side of the field, and boogey down the line, almost like a slapper in softball.
Now, on a personal note, my DD is 12, soon to be 13, and pretty good size, a little over 5'6", about 110 lbs, and pretty strong for her age. She fell in love with softball 3 seasons ago (after playing coed T-Ball and Pony League (machine pitch), it all clicked when she went to all girl teams) and I started really working on her hitting.
I started her out the way I was coached almost 30 years ago....hands to the ball, squish the bug, etc....basically, I know now, linear mechanics. And, she did pretty well in Little League, even all stars. She never cleared the (200') fence, but she came very close several times, both in practice and games, and even all stars against "better" 10U and then 12U pitching. Our local little league had a home run derby last summer for a fund raiser, and she got 2nd in her age group (boys and girls), hitting 4 baseballs out of 20 over the fence, never mind that she hadn't hit a baseball in almost 4 years.
But, she was also playing travel ball, and playing up to 14U. She still did fine against most pitchers, but against the few really fast ones, she had a real hard time catching up to the pitch. I knew that her swing was kinda "long", but I didn't know how to fix it. Then I changed jobs, and one of my new co-workers was a guy who had worked with the local high school for years, and been to several swing clinics, etc. He saw a picture of her pitching, couldn't believe that she was only 12, and asked me if I would let him look at her swing one evening.
Well, the way he teaches swinging is a little "hybrid", I've figured out since I've been trying to educate myself a little (mainly he still teaches a slight "down-swing"), but mainly he works on them using their body to swing the bat, rather than the arms like in a more linear style. I could tell that it made her swing quicker, and it was proved to me when in her tournament that weekend, she was out in front of a lot of pitches....she was starting her swing at the point where she had previously, but getting the bat to the zone much quicker. She faced the fastest pitcher we saw last year (this girl had to be pitching in the upper 50's, close to 60, which is pretty fast for a 14U around here), and the first time up she hit the ball solid on her....and pulled it foul.
I knew right then that I had to continue to work on what my co-worker started, because I could obviously see the difference in her bat speed. I figure the quicker your swing is, therefore the longer you can wait to make that decision to offer at the pitch or not, the better off you are. Plus, it just makes sense that a swing coming from your legs and torso has more power than a mostly-arm swing.
So, I've been trolling every web site that I could find, ordered a couple books on rotational hitting, etc. I know it's not gonna happen overnight, but I'm confident it's the right approach. Plus, my 9 year old boy needs all the power he can get, he's tiny, unlike his big sister.
As to the path of the ball, release point, etc, yes, there are differences...but, the ball is still on a downward path when it crosses the plate. Not exactly the same path as a baseball released from overhand (and from a mound), but similar. Even a rise ball isn't "rising" as it passes the batter, it just isn't dropping as much. Plus, they're usually high in the zone anyway, and a rotational hitter should have a flat (or almost) flat swing in that area anyway.
Shew, sorry so long
But, you said you were wanting disussion
(I even had to type that on my laptop, which I hate doing
)