Still on Act 1 Hell.
I ditched Soul Harvest because not getting hit is better, the Int increase is situational, and I sorely missed having locusts. Honestly the only reason I tried out Soul Harvest for awhile is because every single build seemed to have it.
I just now got Healing Journey for Spirit Walk, but I haven't gotten to try it out yet (I've been using Jaunt which has worked pretty well for keeping me alive). I plan on getting Life to Hit the next time I find a great weapon that has a socket since I'm hearing glowing testimonies about it.
Also, how is Fireball (Flash Fire) in Inferno? I use it against large packs of enemies as an alternative to Spined Poison Darts (I don't have Zombie Bears yet, not a fan of a lot of the other costly AoE spells).
I have a 60 Witch Doctor that I've played in Act 1 and Act 2 of Inferno so far.
In Hell I had absolutely no problem using Soul Harvest, in fact I would encourage it... along with the Siphon rune it's a great ability. Run into mobs (not Spirit Walk), smash Soul Harvest,
then Spirit Walk out of them and begin spamming AoE... and actually if you have Zombie Bears, don't even run out, just stand in the middle while Spirit Walking and throw bears like crazy. You get hit while running into the pack to Soul Harvest but when you get there and use it, the Siphon rune will heal you and then you Spirit Walk to escape... with Bears you Spirit Walk to activate the mana regen rune so you can spam that shit - that's pretty much the gameplan.
Now, in Inferno, getting hit even once or twice by a most enemies isn't really an option so that strategy goes completely out of the window. You technically could Spirit Walk, get close to enemies, Soul Harvest, and then back off before Spirit Walk ends but it's very risky and, more often than not, you won't get a full 5/5 stack nor will whatever rune you have be very much use. Assuming you safely outgear whatever act you're farming in Inferno there are some slightly viable strategies with Soul Harvest but otherwise I don't find it useful anymore. When you're kiting around a couple of Champions for 3 minutes what's the point of Soul Harvest anyways?
As for Firebomb in general, I used it from the moment I learned the spell to about 10 minutes into Inferno when I switched to Darts (Splinter). The problem with Firebombs is they don't do enough single target damage for taking down Champions/Uniques/Bosses and they're relatively slow. On the other hand, Darts aren't only quick and do tons of damage, they're
amazing because there's practically
no limit to their distance. You can literally shoot monsters far off the screen, unlike firebombs you just give them a direction and they go for what seems like forever until they hit something. On the same token they're amazing in that they almost stagger-lock enemies, since the damage is high and you hit them with so many darts they're just constantly recoiling... which means they're constantly interrupted from casting, attacking, or even moving.