Hi AMW. I purchased a lightly used unit about 6 months ago and love it. The dual roll feature is a time saver. The color and speed is incredible and beats the brakes off my HP 360 Latex. I've never been blown away by posters coming off the latex but it has come in clutch from time to time. The Epson pops and the color gamut is much wider, especially since there's a gray ink channel. Borderless printing side to side (not top to bottom) is a great feature and cuts down production time. You can run Epson treated poster board through it as well but from what I hear the board is really expensive but could be a money maker in the right circumstances. The P8570D has a dedicated PDF RIP onboard with an embedded processor that crunches those big complex files with raster and vector elements in lighting speed. Epson software is pretty average but allows you to update media and sizing fairly easily.
Were there any specific questions you had beyond what I mentioned here?