Good afternoon Jonz!
First - I want to clear something up: debating which of the ST1100 or the ST1300 is faster is a bit....hmmmm....pointless in my view. It's sort of like trying to decide if a lemon merengue pie tastes better than an apple pie or if Cheryl Tiegs is prettier than Christie Brinkley. It's a personal thing and NOBODY is wrong.
The fact is that BOTH motorcycles are stupid-fast and ridiculous-quick, as is nearly every other modern bike.
I've owned several bikes over the past 40 (holy cow!!) years and the fact is that ANY of them - from the Honda CB360 to the Yamaha XS650 to the Suzuki GS850G to the awesome Honda ST1300 - are fast enough and quick enough to KILL me. I will admit here and now that I have actually NEVER used full throttle on my ST1300. I did it once on the GS850G but that was 1982 and I was younger and....much less wise. The ST is great - and it's really nice to never be short of power for carrying a friend, passing a string of slow pokes, climbing big hills or just for a bit of horsing a round (I may be old - but I've still got a pair) - but to actually open it up and hold it at full throttle for any length of time would a bit nutty (and would certainly result in the loss of my drivers licence). OK - sermon ended.
Now, to Jeff's question: yes, mechanically driven superchargers do consume a significant amount of power while being driven. I don't know exactly how much, but based on the fact that an AC drive consumes around 7 HP, I'd guess that a supercharger drive probably requires 10-15 HP, depending on engine and blower size. HOWEVER, modern supercharger drives have a electrically operated clutch (much like an air conditioner clutch) - that disengages the blower and thus greatly reduces drive losses when the supercharger is not in use. The control on that clutch basically "decides" whether to engage based on throttle position, engine load and other operating parameters.
A turbo-supercharger also represents a loss to the engine because it imposes back pressure in the exhaust tract - even if the turbine is just idling. However, some systems have valving which removes the turbine from the exhaust tract in low power demand situations. Also, the turbine responds to signals somewhat like a mechanically driven blower clutch, but generally there is less active control of the blower (or compressor as it is more correctly known). Some modern systems also have a variable geometry feature on the turbo inlet which optimizes system response to reduce turbo lag. All modern systems have very sophisticated engine controls on spark timing and the fuel-air mixture to keep operating temperatures, boost pressure and turbine rotor speeds within limits and ensure that pre-ignition doesn't burn holes in pistons or valves.
The fact is that automotive (or motorcycle) superchargers and turbo-superchargers are normally used for short periods of time. I'd guess just a few seconds at a time. I saw an estimate once that most automotive engines produce full rated power for less than 120 minutes over their entire lifetime. In contrast, an aircraft or marine engine operates at, or near, maximum power for MOST of its lifetime - so they are pretty different creatures. That is one reason why auto engines are seldom used in aircraft and even in marine service, they require pretty significant modifications particularly to the cooling system (marine engines normally have cooled exhaust manifolds). The aircraft and marine operating regimes are really entirely different from on-road vehicle use.
The key thing which I think that everyone understands is that either a mechanically-driven or turbine-driven intake compressor is a darned effective way of increasing horsepower - BUT - there is no free lunch and if things are not controlled very carefully, engine life will be very short and the fun will end - expensively.
Hope that helps!
Pete
, a 
& a 
; they are all fastest! 
