I like it too. I think that it's because you see your penis much bigger in the pumped state and that's sooooo cool. I love the feel of my dick after a good girth workout and that's highly motivational. And, of course, it feels pretty good while you're doing the girth work too. Stretching is nothing like that.
For myself, girth work is best. It's such an incredible pump : horses, uli's, slammers, especially with the ROP. I like the resultant heft. Luckily for me, I don't care about any more length than my current 7" bpel, so I've been doing strictly girth work for weeks.