John M.,
Yes, the supercharger kit from EE comes with two tunes, one for high-performance (more advanced spark timing, etc), and one for lower performance (if you got some bad gasoline or something). I've been running the high performance tune since about 2 hours after I got the supercharger installed and haven't had a bit of trouble with knock/detonation. I am running 93 octane though, because that's what's available close to me. However, I doubt that you'd have any trouble at 92 or 91 either.
We've had days where the temps hit 98, and so far, I haven't had any problems. It was down to 36 last night. I got it out very early this morning and it ran like a bat out of hell, just like it does despite the temperature. If you're concerned about the temperature, you could put a "boost cooler" on it. I am considering it, it's $399, and it can give you up to as much as 75 additional horsepower, and cool the intake temperatures. I'll post a link at the bottom for you to check it out.
As far as the low end torque goes, the supercharger simply cannot be beat. When you mash on the pedal, you GO, and you go FAST. I went up a 17 degree grade today in top gear, doing 70mph and the truck never shifted down and held every bit of that speed without giving it hardly any gas. You'll swear you've got a big V8 in it, until you go to the gas station, where you'll be pleasantly reminded you're still driving a V6.
I don't really know how this compares to the lightning because I've never had the opportunity to drive one, however, I suspect it runs very similar to the supercharged 'Trac.
If I had to choose ONE performance mod for a sport trac, it would, without a doubt, be a supercharger. It makes the truck a LOT more drivable at highway speeds. When you jump out to pass someone, you don't have to WORRY about not making it around in time because you will get up to 80mph in the blink of an eye. It's really not something I can EXPLAIN.
On my Pioneer vehicle performance monitor, I was pulling well over .5 G at 80mph. A non-supercharged sport trac barely pulls .5 G from a standing start. It's truly a night and day difference. If you want all the advantages of a massive V8, without the crappy gas mileage, then there's no question that a supercharger is what you want. Of course you could always go out and cram a 351 in there...but say buh bye to your 20 miles + per gallon. hehe
Anyway, if you have any more questions, feel free to ask.