About necros it kinda loses interest it seems, if magical / disease increment doesn't work on lifetaps like Lifebane/Gangrenous (why ? they're more than 300 mana) and the last tick of the dot is the least likely to be seen - speaking in group situations mainly.
I guess it would be too complicated to spread them like rains although it would make the most sense to me. Would it then be overpowered to do exactly the same, but first tick ?
I was responsible for the (initial) coding for this change, and my only SoD character is a necromancer, so let me try to explain what was going on in my head for this. I would have preferred the damage to be spread out evenly across all ticks, but unlike rains (which are always 3 waves), DoTs vary greatly in tick duration. Besides alot of extra division every time a spell is cast, rounding becomes a huge deal, in some instances for some of the longer dots, making the bonus near meaningless.
For example, lets take the 6 tick Marlows Creamation, a very bread and butter DoT for most Necros. Assuming no other bonuses, if you had +12 fire dmg, the damage would go from 420 a tick to 422 a tick. Simple 12/6(tics). But if you had +13 fire dmg, 13/6(ticks) would net you 2.1666 dmg bonus per tick. Only due to how all the rest of spell coding works, it would actually only be 2 dmg bonus per tick. Same with +14, +15, +16, and +17 fire dmg. The problem is compounded further with a spell like Splurt or Scitterpox.
The choice then became, pick an arbitrary point to throw in the whole bonus, or give free damage to necromancers by adding the dot duration to the elemental damage bonus. The second is not reasonable, and I didn't like the idea of rounding bonuses into oblivion. At least with mages, the rounding is consistent for every rain; we can fix that rounding error if we deem it a big issue with minimal extra computations. It really isn't elegantly possible with DoTs.
300 mana was chosen, again, arbitrarily. It was not our intention to exclude enchanters, simply an over sight we didn't discuss properly. Lifetaps currently do not gain anything from +elemental damage, as they are not considered 'nukes' by the spell engine, which is where the changes went in. This is due to fears of unbalancing lifetaps from weapon procs and Shadow Knights, more than a sleight against necromancers. It is unlikely to change unless some VERY good reasons can be thought up.
Many games have the +elemental damage. I played WoW and am VERY aware of the ridiculousness that +elemental damage on say, a Warlock, had. This was due almost entirely to bad itemization on Blizzards behalf, and the only good solution, is good itemization and drawbacks for stacking elemental damage. At the moment stacking really isn't possible, but rest assured that those who choose burst may find longevity hurt. In my opinion choices are the bread and butter of MMO's (even if it will mess with the top 5 list a bit in the future).
This change went live before Ikisith for reasons that pretty much are this thread, to get the bitching and complaining that any change (even changes that only help the player base) tend to bring. So feel free to keep complaining and adding good points and oversights to this discussion. It only makes the game better.