Powercolor, Asus, Sapphire, and MSI have non-reference coolers IIRC. I think the reference cooler does a good job of cooling but is set up for quietness so it runs hotter unless you up the fan speed a bit. The XFX 4870 I got had the reference cooler but since my comp is watercooled it was loud for me and I ended up watercooling it(I guess it's subjective but I can actually hear hard drive seeks so I prefer my comp very quiet). And the best thing about the reference cooler is it exhausts hot air out of the case....none of the non-reference coolers do that. Also, the mem and VRM cooling becomes a problem with some of the non-reference coolers (I don't think the Asus version comes with any cooling on the ram).
About the 5800 series...I think it's too early to tell if it's on track.