ITP probably does make the best tire all around the mayhem tires are pretty good. I also thought the blackwater models were designed for a utv but wouldn't see why they wouldn't work on an atv. I have same quad as you but 2014.
The 28" Blackwaters are apparently lighter than the 28" Mega Mayhems according to their website AND 8 ply as opposed to 6. I also read they measure a true 28 inches whereas the mega mayhems did not. I love my Mega Mayhems but very tempted to try these Blackwater evos next
I use the 30" Evos for a trail tire on an XMR 1K and they work great. Smooth riding and fantastic on rock to mud. Have only had them in light mud/clay but they bit very well.
Looking at the 27" Blackwater. Living in Bend, OR and riding in Mtns. of Idaho we do not see a lot of mud. Most riding is trails with sharp rocks and sticks. Still have stock tires, not sure why I have not got a flat yet?
Will I need any spacers with the 27" Blackwaters?