Which model did you go for?
i got the xx14 while i owned my CBR it fits a few bikes ive owned including the GS
so are disc locks, cut either side of the unit and the section of disc just drops out and the lock can be removed and the bike wheeled away
that would take some doing, plus the screeching alarm would be going off constantly.
either way you look at it, its better than parking your bike with no security at all?
plus you can connect a good bike chain to the disc lock too making it an even better deterrent.
i usually put a disc lock on both front and back wheel.
my other disclock is an oxford one, which even to just look at is rubbish compared to the Xena version, but its bright yellow and a visible deterrent
the Xena is solid and feels tough, it would probably be easier to cut through the brake disc than this.
my only complaint in 8 years of owning it, i went camping and used the lock and don't know why but the alarm kept going off for some reason the whole campsite could hear it!
i had to remove it and take the alarm battery out and re attach.
it had been raining very heavy, so maybe water got inside it? dunno but its never done it since?