Drums of Restoration

[Brutone]

Does anybody know the range of https://tbc.cavernoftime.com/item=29531?
When comparing https://tbc.cavernoftime.com/item=29531 to https://tbc.cavernoftime.com/item=29529 and https://tbc.cavernoftime.com/item=29528 I noticed that it gives significant more stats than the other drums.
To determine the stat value of mp5 I compared https://tbc.cavernoftime.com/item=32202 to https://tbc.cavernoftime.com/item=35761.
https://tbc.cavernoftime.com/item=29531 gives 200 mp5 which would be the equivalent to 500 haste rating or 32% haste.
Even when taking into account that https://tbc.cavernoftime.com/item=29531 has only half the uptime of https://tbc.cavernoftime.com/item=29529 it still gives like 3 times the stat value, not even taking the healing effect into account.

Does https://tbc.cavernoftime.com/item=29531 have any downside that I'm missing?

[Kalola]

One of the downsides is that haste from battle increases everyone's damage and healing, while restoration only restores some mana. If you kill boss faster then you need less mana, and not every class uses mana. Also fights jsut generally don't really last long enough for mana to be of concern to anyone but healers and arcane mages.