I think it all depends on what you're trying to achieve.
I was always a shampoo only person because back in the "old days" I used a couple cheap nasty wash and wax's which left the paint cloudy, streaked and looking horrible. Then a couple years ago, that all changed.
My first introduction to quality wash and wax products was DP (now McKee's 37) Power Wash. Not only is it slick with great cleaning ability, but the little bit of wax in the product leaves the surface really glossy and slick. From there I tried out Blackfire's Wet Diamond Conditioning Shampoo. This product was close, but a little behind on good as McKee's in the slickness and cleaning ability, but again left a really good shine when done. On metallic paint, I actually preferred the look of the Blackfire.
In both cases, I never had any of the issues associated with the old wash and wax products. Both left the paint clean, feeling slick, and really glossy. Due to the embedded wax, the cars were very easy to dry since a flood rinse would sheet off most of the water. I found with these products I wouldn't need to break out a spray wax to aid in drying or boost the shine.
These products don't get a lot of discussion, but I think they have their place in the consumer market. I wouldn't count on them to be your LSP, but they are a great maintenance wash product.