On the money...
I'd have to agree with JR SPEY on the thoughts about running line and SA's obsession for distance. I've quit using them as well.
99% of the time, the first cast to a bone doesn't get it done. Quick, accurate recasts are essential, especially on those all to common occasions when the angler doesn't see the fish. Over the dark turtlegrass flats we have here, I regularly guide the casting/stripping of my anglers to get them into bones they never see, until we land them. Now, I obviously would much rather have the angler see the fish - they can make a better presentation then - but that's not always possible when a fish is coming at you and you're running out of time. Shooting heads might load quickly (no arguement there) but they don't allow for quick pickups, which are absolutely essential in flats fishing (bones, tarpon, permit, reds, etc.). A good flats line (Cortland or Rio) will give you that option, although you still want to match your line for they type of fishing you'll be doing that day. (ie bright sunny day with great visabilility for bones and anglers might require longer shots, but an overcast, windy day might necessitate quick, short shots.)
The other reason I'd venture to say shooting heads would be a less than idea choice is that they generate way too much linespeed. This would make a delicate presentation very difficult indeed. Also, the sound of a flyline hitting the water does indeed spook fish, and heads are definitely heavier. That's why so many bonefish guides I've fished with love sidearm casting - the line doesn't fall from such a height so the splashdown is minimized. On calm, clear days (especially around the full moon) I regularly see bones change direction after they hear a line slap water. On those day's I've gone down to a #6 rod/line settup and started catching fish again. They just don't hear that light line hitting the water as easily.
Speaking of which, if you can cast well, don't ignore those lighter rods. Personally every time I travel to fish the weather is lousy (blowing 20-30 and cloudy) but I have had a handful of days where a lighter rod made the difference. (Tarpon in the Keys and bones in Bahamas and Little Cayman.) Carry a toy when you go, sometimes that lighter rod/line can be on the money.