Why does Merrell keep messing with a good thing?  My first pair of Merrel's was a pair of the Chameleon 3's and they were an incredible fit right out of the box and lasted for years...I still use them for yard work.<br /><br />Then I got pair of C4's and overall they were a step back.  The durability has been pretty good, especially since they felt cheaper than than the C3's they replace, but they have held up nicely.  But, the fit has never been right and even after a long time of wearing, they are less than comfortable.<br /><br />So, when it came time to buy a new pair, I was nervous.  The new Primes looked more like the C3 and the garish colors were gone, so I thought I would give them a try and just like the C4's it is mixed bag.<br /><br />One of the things I liked about the C4s were the Vibram soles, they were durable and gave good traction without tracking too much of the outdoors...indoors and that is gone.  The new soles look more like the C3's and they weren't bad, so I can live with it.<br /><br />The toe and heel guards on higher than the C4's, which is a good thing and the overall construction seems a little more durable, but the problem is once again fit.<br /><br />Once, you get these one, they are actually pretty comfortable...definitely much better than the C4's...but someone decided to make the back of the shoe higher, which leads to the foot opening being much smaller and incredibly challenging to put.  I could slip my foot into my C3's with no assistance and the C4's usually need a finger to straighten out the edge of the sock, but the Prime's require both hands and quite a bit of jiggering to get on.  Once you get past this, the fit is pretty good.  Not sure what they changed about the sock, but these shoes are definitely hotter than the C4's and a lot hotter than the C3's.  Not sure I could wear these all day on a Summer day.<br /><br />Finally, that extra height at the back of the shoe changes the appearance and it is hard to notice in a picture on Amazon, but the C4's stop about an inch below the ankle and give plenty of wiggle room, but the Primes run right up against the ankle and could lead to rubbing when walking on uneven surfaces.  I can see where the extra height would be beneficial when walking in wet environments, but it just doesn't work for me.<br /><br />I  am pretty sure these shoes will hold up for quite some time, but I am not excited about spending a couple of years with a pair of shoes that are uncomfortable like the C4's were.