Should you switch to the h7 - from, a 212 evo? If you already have the 212 evo, keep it. The difference wouldn't be enough to warrant spending on a whole new cooler like the h7. Unless you're having heat issues, then I would consider a better class of cooler like the phanteks tc14pe, cryorig r1, noctua nh-d14/15 - the big air coolers. The h7 is a better budget cooler to get for someone who is shopping for a cooler say to replace the stock cooler and is choosing between the h7 and 212 evo, rather than a replacement for a 212. It would be more of a sidegrade than an upgrade.
The 212 evo isn't a 'bad' cooler, just an older design and improvements have been made over the last several years since the 212 evo was introduced. Better mounting, improved orientation to reduce ram clearance issues etc. I have a 212 evo on a 4690k running a low overclock at 4.2ghz and it's in a hotter room of the house that gets a lot of sun. It cools it just fine. Unfortunately I bought it and a few months later cryorig introduced the h7. If the h7 had been out I would have gone with it instead but it's not enough of an upgrade to warrant fiddling with removing the 212, buying and installing the h7 in its place. It's in now. I don't personally care for the 212 evo's mounting, it's a bit flimsy but it does the job. The system it's on is running 4 sticks of ram so the ram fitment was a bit of an issue. Thankfully 2 of the sticks were low profile, I was able to insert the low profile stick closest to the cooler so it fits below the fan. Even with a normal height ram stick in the 2nd dimm slot from the cooler, snapping the fan in place was a little fiddly. Not impossible, just more tinkering than was necessary.
Despite its massive size by comparison, the dark rock pro 3 installed much easier in my opinion. No center knurled nut to try and tighten with my fingers, no scissor action X shaped mounting bracket. Just install the backplate with the standoffs, place the cooler face down, rest the motherboard on top and screw it down. Rock solid. Also something to keep in mind, pain in the rear or not a cooler doesn't typically get taken out and installed over and over so once it's in it's in. For me it was just a minor gripe but if there are easier coolers to deal with why struggle if you don't have to right?