Okay, I tried one.  I also tried their Flex Drive pedal.  Impressions of both below, starting with the Flex Drive.

Flex Drive:  I wanted to like this pedal because the demos sounded pretty good, and it was designed by Brian Wampler from Wampler Pedals.  Billed as an extremely flexible overdrive pedal with two different clipping modes or clean boost, and with two different high cuts, or none.  My demo unit had two problems with it.  First problem was the tone pot was scratchy.  Second was that the gain just dropped out on several occasions while I was messing with the tone pot.  Something not right with the unit.  Maybe something loose inside?  Opened it up.  Construction seemed pretty good.  Tried fresh battery, although the included battery was putting out 10.1 volts, so obviously fresh.  When the unit worked, I was less than impressed with the tones I was getting through my amp (Mesa 5:50 Express).  Nothing here that you couldn't get from pretty much any OD out there, but maybe less so.  With the problems I was having, the unit went back.  I will not order one.

Animal Overdrive:  Oh man!  This one lived up to its billing: a plexi in a box.  And not just one plexi, but two: vintage and modded.  Very open and organic sounding on the vintage toggle setting.  Made my Mesa's clean channel bark like a vintage Marshall.  Treble and Bass controls are extremely musical throughout their entire range and really help in dialing in the tone.  Flip the Snarl switch to the modded position and you are in hard rock territory.  Solo or rhythm work are equally good on this channel.  I took this one to a worship service and used it the entire time with just my volume knob and pickup selector to go from clean to crunch to dirt.  The other guitarist was a pro who played with a well known act on their TV show, and he inquired about the pedal because he really liked how it sounded.  I ran the pedal in the effects loop of my M13, and I gotta say that for as good as the ODs in the M13 sound, this is that much better.  Very amp-like.  What to do about liking both modes and not having both available on command?  I ordered another.  LOL!  A side benefit of running the the M13 loop is that I can put a boost before it for more gain if I like.