garmin 496 - truning on and off mo xm subscription services....

I am about to activitate my garmin 496 weather and music features
w the xm folks...

I am going to use the "full blown" weather service @ $50 + $7 for the
radio feature.....

Two questions...1) if I know I am not going to use the features for
say
2 months ( or longer ) ...can I temp. turn on and shut off w/out
penalities
or fees?

Or, does one need to keep going, month to month using the services it
or not?...and 2) whats the music quality like on the radio side? How
do
folks listen to the music ? ... Get a good set of headphones?
Portable
speakers? Or just use the built in factory speaker?.......

As always...thanx for ideas, comments, and tips.....

cheers.......