What's a better guitar strap?

What is your guitar strap? What are the factors of a strap do you consider? What is the most essential to you? the good looking or the comfortable one?

         This questions are very important in choosing a guitar strap. For me, I'd rather choose the comfortable one than a good looking strap. Why? Because the looks won't affect your playing especially in a long playing situation. I always experience shoulder ache and back ache every after playing sessions, and even while playing! Of course, that aches affects my playing and I don't want that. But after I got a "Mono GS1- Betty" strap, the suffering has come to an end.

This strap in my opinion, is the most comfortable strap ever. because of its wide wale design which distributes the weight of heavy instruments. A thin memory-foam core reduces fatigue during long hours of play. A smooth Neoprene underbelly lets the shoulder breathe and slides nicely across your shirt or skin. "Forget about the instrument. Concentrate on the music".

I strongly recommend this strap to all guitarists out there! here's their website.
http://www.monocase.com/mono-gs1-betty.asp