To give you some ideas... Well, I used MD during training, but I left it at 1/5 until I reached lvl 40ish to max it. I was testing to see if the damage throughout the MD animation was more than my single critical 1/ 5 DB. The total damage of MD throughout the 3 seconds was better than my fully charged, critical hit 1/5 DB( though, it was not very noticeable.) So my fully charged DB was at 52%, and crit to 104%. MD was only 84%, but the total damage during the animation dealt more( due to poison, some critical hits of MD, and the auto attacks). What I am trying to say is a single critical hit DB at 1/5 deals almost as much damage as the total damage of MD during the whole 3 secs animation.
Now after having maxed MD, it seems to be doing like almost double damage of the DB at 1/5. If I remember correctly, as of now my poorly geared rogue does around 300 for a non critical DB, and 600 when it crits. Most of the times, my MD at maxed level does about 1000 in total( including the poison and autoattacks.)
So from my observations, what I am trying to conclude is that a maxed MD is clearly stronger( almost twice as stronger) than a single, charged, critical hit DB. I believe it appears to be almost twice as strong because of the autoattacks, some critical hits, and poison during the animations.
BUT if you want real math without factoring in the autoattack and poison hits:
110% / 84% = 1.30952380952, or about 31% more damage for maxing MD.
For 3/5 MD, 97% / 84% = 1.15476190476, or 15% more damage.
I apologize if that is confusing. Basically, what I want to say is that MD is stronger than DB with only 1 skill used( this makes it effective as a finisher for those half-dead runners.) DB has the potential to deal more damage because it's faster and CM procs, but you need to use multiple skills to be stronger than a single MD( this can be a problem against runners.) So yeah, to answer your question, you get about 7.5% overall damage more for each level of MD. And yes, it is quite noticeable, especially in comparison to the damage of my single DB critical hit, after having it maxed.
BUT THEN AGAIN, MD is currently glitched with the final hit. The critical hit modifier isn't working properly. It probably will be even stronger when after they've fixed it.
Anyway, hopes that help!
Edited by ZT0100, 19 August 2013 - 02:27 PM.