I agree with all of the previous comments. I would add, though, that the high power capability of the amp relative to the rating of the speakers increases the importance of observing the proper turn-on and turn-off sequence. The amp should be turned on last, after all of the other components that are being used are turned on, and the amp should be turned off first, before any of the other components are turned off.
Otherwise if the design of an upstream component is such that it is not well behaved at turn-on or turn-off any transient it might generate at those times could potentially be amplified to the full power capability of the amp. If the transient is very brief, meaning that its spectral components are at high frequencies, 250 watts or more could briefly be sent into the tweeters.
I once had an S300, and I recall that it could continue to play music for about 40 seconds or so after being turned off. So after powering it down, it would also be prudent to wait for that amount of time, or longer, before turning off the other components.
Regarding the question Mark and Roscoe were discussing, while it is true that the volume control settings that will be used are a function of gain, amplifier gain and power capability will tend to have a loose correlation, so Mark's observation was not entirely invalid. Amplifiers tend to be designed to be driven to full power by input voltages that are in the same general area (1 or 2 volts or so, for unbalanced inputs), regardless of how much power they can generate. Therefore a high powered amp will more often than not require a significantly lower volume control setting than a low powered amp, everything else being equal.
Regards,
-- Al