When I bought my first trailer, we got a set of the CIPA mirrors. One trip to Florida, and I knew I wanted to upgrade to the HD mirrors. They are HUGE. Did it on both of my Suburbans. The set I got for my 08, with heated top mirror and outboard LED turn signals, was $275. Only downside is that, unlike the GMT800s, you have to take apart the whole door because the mirror plugs into the window switch. Took about an hour for me and a buddy to do it.
I love the lower convex mirror, and the upper mirror works with the memory seat function.