I use Portra 800. I like it quite a bit. Grainier than the 400 varieties obviously. It works well for me in tungsten lighting though seems to be really sensitive to the green from fluorescents. What's odd about the green though is that it's not a sickly green but a really rich green. As a result, it's been pretty easy for me to correct out (digitally). I also find it to have a bit of a different color balance than the other Portra's and to be more saturated than it is stated to be. Again, I'm scanning, so take it with a grain of salt.
Here's a couple shots from the most recent version (800-3). If you right click on the photo and select original, you can see them at the full scan size - some are up to 4k x 6k. Portra 800-3 samples