I've followed the arguments back and forth on this spell for a while now. Revitalize continues to be both nearly essential and absolutely worthless in my mind. Some numbers from our last deathwhisper fight (for reference I'm 3/3 in Revitalize):
RJ: 371 mana x 157 casts = 58,247
WG: 643 mana x 16 casts = 10,288
No: 559 mana x 35 casts = 19,565
RG: 719 mana x 13 casts = 9,347
LB: 293 mana x 15 casts = 4,395
total mana used: 101,842
total fight time: 430 seconds
net mana drain = -236 mana/second
Total regen on me due to Revitalize: 4,742 mana
Total regen due to Innervate (for comparison): 6,262 mana
With that consumption rate I get an extra 20 seconds before OOM thanks to revitalize procs.
On one hand Revitalize is nearly worth the same as an Innervate to me mana-wise. Innervate is awesome, but thankfully doesn't cost talent points. In a 7+ minute fight like this one, Revitalize opened up an Innervate for someone to use. On the other hand, I wonder how often am I going to be in that extra 15-30 second window where the extra mana gained is essential to survival? *shrugs* Though I do like having an Innervate to share.
Once again, it seems like it's awesome if we need the mana and worthless if we don't. Or does someone have a better way they weigh this one? Sometimes I feel like I'm buying insurance: spending the extra points on mana-regen I hope I'll never need to use it.
One good thing at least, there's really no other practical places for me to put the talent points atm. ;-)
Oh well sometimes it helps to put your thoughts on paper, or da interwebs as the case may be...