On my car, I'm running around 13psi of boost.
Ok guys, in order to have a meaningful discussion on AIRPLANES we need to remain in the realm of reality.
First off, 13psi = about 26" of MAP boost! Holy pizza, Batman - that should take you to 50,000' on a bad day... That sort of overboost is not recommended in any production aviation engine today - and pardon me if I respectfully decline to go flying in any RV fitted with such a monster turbo! Had my excitement flying supersonic young, now working on "old pilot..."
Next, you talk about RPM ranges. Hello, 95% of aircraft flight time is spent between 2000-2700 RPM - only a 27% rpm difference. There is NO NEED for "low end boost" because we aren't looking for torque "off the line," so clearly we can simply tune for the high end.
5 psi of boost should be enough to maintain 75% power up to nearly 17,500'. I don't know of an awful lot of RV flyers who routinely put on the nose bag, and cannulas are fine up to 17,500.'
Going back to our AIRPLANE scenario, with only 5psi of boost at sea level full power available (maybe 6, as it might not be as effective up higher) you can get by without an intercooler using a supercharger. You can also "get by" without an intercooler using a turbo, but the consensus is shorter TBO. In either case adding an intercooler improves engine life, with the advantage still to the supercharger. But, if you don't have the room for the intercooler, then the supercharger starts making a lot more sense.
As for it being like "driving with the AC on" - Instead of thinking of it as "an extra 10" of MAP," think of it as an additional 7.5" of MAP with a small fuel flow penalty. That penalty is likely to pay for itself in engine life if you go the no intercooler route, and possibly even if you do install the intercooler.
So, it all comes back to how much heat are you willing to add to your intake? The graph below compares supercharger solutions; I can't find the graph I once found that added in turbos for comparison but they added about another 100 degrees...:
This article discusses the differences between them, particularly noting:
"A centrifugal supercharger on the other hand creates a cooler air discharge, so an intercooler is often not necessary at boost levels below 10psi."
This is the key difference which makes a supercharger a viable alternative (I'm not saying "better" or "worse" - just a reasonable alternative).
Finally, there is that pesky problem turbos have with lubrication. Spinning at 20,000 rpm using engine oil and powered by 1400 degree exhaust gas, sometimes folks forget how carefully balanced they are in terms of engineering. Shutting off your engine too soon after landing can result in the oil "baking" in the turbo, preventing oil flow next time you start from cooling / lubricating your turbo. Bye bye turbo. It may also result in nasty sludge entering your engine from the turbo.
Ok, I've had my say. For those absolutely certain that a turbo is the way to go, knock yourselves out. But let's keep the conversation in the realm of the reasonable for folks who might want to know all the facts. The reality is that each has it's strengths and weaknesses, and both are more complicated than normal aspiration.