I have withheld judgement on the DMR until I had plenty of experience with it. Here is my opinion.
I like and dislike the DMR Bloom. My problem with it is by three shots of spamming, the bloom is outside is crosshair circle. Now this is where Bungie messed up. After three shots RNG is introduced (maybe a little bit on the second shot but not enough to really make a difference). For those of you who don't know RNG stands for Random Number Generaton and its something most game developers try to avoid because it introduces too much luck. This means that while shooting your last two, three, four , five and so on and so forth shots, the bullets can go anywhere in that huge circle. This is a problem because it means at the outset of any DMR battle the luckier player always has a chance to win instead of the most skilled.
For Example, Lets say you do like I do and spam your first 3 shots, wait for the bloom to come down then shoot the last two. This is an effective method, but even if I do that perfectly, 5 headshots, the other player still has a luck chance if he spams all 5 to win. This is not based on skill but pure luck. Some people may like this. But those people are usually people with inferior skill who must rely on luck to kill better players.
My Solution: I am fully aware that this will never happen but here goes nothing: The DMR's bloom should not come into play until the sixth shot. They should make the bloom smaller to where if you shoot as fast as the DMR can, the first 5 shots hit where you are aiming, then on the sixth and thereafter, the bloom becomes big. This would give skilled players a chance to land a 5 shot based on their skill, and punish them for not doing so. That is my opinion. Sorry it was so long. Had to get that off of my chest.