I use this when playing on stage with two heads connected to two cabinets, so I can have then on my side of the stage even if one of the cabinets is on the other side.
I don't know what there is much to say about a speaker cable... It's pretty thick (and also heavy!) and seems very solid. It doesn't 'sound' (do cables actually sound?) different than any of the shorter speaker cables I was using.
15m is easily long enough for every stage you will get to know (actually, in my case it is mostly too long, 10 oder even 5m would suffice, but the price difference wasn't that high and I wanted make sure...) and I am very positive that it will last for years.