I've used all sorts of harnesses, including the digger and I fell in love with my old caving supplies one. It is basically fully adjustable and simple, in my estimation, you want something which is not like a petzl nappy (industrial jobby), you want it strong, simple and fit for purpose.
On the back of this, I'd go for a Petzl Superadvanti.
If I recall correctly, the singing rock was made out of some nasty material which was stiff as hell. I also didn't like the metal loopy things your D Ring attatched to, they wore the inside of the ring unduly which to my mind was bad design.
Bloody legislation is responsible for Caving Supplies no longer making some excellent products.