I'm writing this review after running in the Mizuno Alchemy 12 shoe for 370 miles.  I was fitted for this shoe in a running store and paid the full list price for them. I've had no experience with the previous Alchemy versions or the Mizuno brand before this purchase. I'm right under 6' and weight right at 200.  The last few years I had been running in a heavy pair of 1201 NB.  My running distance has increased 2 to 3 times what I had been running and I needed a shoe that was light but still provided support.  I'm running 30-35 miles a week.  I run three times a week; a 6 mile, 8 mile and then one long run between 16 to 23 miles. During the course of every week I run on a number of different types of surfaces.  My 6 mile runs are all sidewalks and asphalt.  My 8 mile runs are 1/2 off road, crossing several creeks, lots of mud but no single trail.  My shoes are filthy with sand and mud after this run so I throw them in a cold wash with my running clothes and then air dry.  My long runs include a lot of hills and are usually entirely off road with a third of the distance on single track trails.  One thing I can't do in these shoes is run without socks.  There is a inseam right where the arch of my foot is.  The inseam is not coarse or stiff and I can't figure out why it bothers me but I always get a blister from it.  For me these shoes have held up great.  They are not "trail" shoes but at least 1/2 my time is spent off-road and have done just fine.  I have raced three times in them a 10K road race as well as two trail races of 10 and 16 miles.  I was very happy with them in all races.  I expect that they will still be holding up great in a few weeks when I use them for a 27 mile trail race.
Even with all the washing these shoes have held up remarkably well.  No tears, rips, fading on the outside including the shoe strings.  The inside and insoles are holding up great. For all the different types of terrain the tread has held up great.  I suspect that spending over 1/2 my time off-road has been easier on the soles.  The shoes are doing so well that I plan on pushing them to the 500 mile mark before replacing them.  At 200 pounds I'm considered a heavy runner and I it's great to get 500 miles out of a pair of shoes.
Thanks to the previous reviewers.  I was looking at purchasing a previous version of this same shoe because it was so much cheaper.  However, realizing that this model is so much different than the previous versions I decided to stick with this version of this shoe as it is working for me.