I took this lock on a three month backpacking trip, and it definitely provided me with peace of mind a few times, when my accommodation or transport didn't feel secure enough. The combination is easy to set up, and the cable was long enough (although sometimes only just) in every situation I wanted. My main problem is that really it is only putting off very lightweight opportunists: the plastic body of the lock doesn't feel very secure and I suspect that someone with a hammer/the leg of a chair could break it and swiftly take your bag without any problem. This is only a problem if the person has time and no witnesses, so it might be slightly less use in your room during the day, but would be more use on a bus where people will notice someone bashing at your bag! But then again, in your room, someone could cut the handle off your bag anyway.
Overall, I had a look at heavier duty cable locks (for bikes etc) and decided they were too expensive, and that is probably true: in 99% of situations this lock will give you the peace of mind you need, but if you have a bigger cable lock handy or can borrow one, I'd take that.