Yea it's useful, but if you've got like alot of of variation in the sample you want to loop it can be difficult to get it to loop in a seamless cycle, also that technique above basically speeds the sample up to increase the pitch so if it does have clicks or whatever in time with the track they might not take to kindly to the speed changes in releation to the rest of the track, but sometimes it can be cool as well i used that loop on the bass in this track http://forum.bandamp.com/Audio_Review/5727.html where it was just 1 'wow' sound then loop it and bobs your uncle and the speed variations have a nice effect