I also own an 870, which was replaced by the 820. I dabble in nature photography, and the Epson photo printers produce the best quality photo prints I've seen in an affordable consumer inkjet! I've got inkjet prints that you'd swear were lab prints. Also, Apple released updated drivers for many Epson printers, through software update in OS X, today, and I'm pretty sure the 820 was on the list.
The HPs do a good job, although they are only four color printers, whereas the Epson Photo 820 uses a six color system. This gives you two extra colors, light cyan, and light magenta, to do a better job on skin tones and the middle color range.
[ 01-04-2002: Message edited by: KarlG ]