In short, the question Im trying to work out is the overall effect/usefulness of avoidance.

I have Everliving bramble tunic atm, which has +25, and if magelo is to be believed (mine is a little out of date but more or less correct) I only have 69/100 avoidance with this equipped.

I would dearly love to upgrade the tunic, even if only to the Scratched hide, but that would cost me 22 avoidance (scratched has 3 avoid). It does however have a few other stats that mine doesn´t have. Given that next upgrade will likely be my cloak, there goes another 10....

Playing on Zek which has a lot of melee players (well that and wizards), avoidance is perhaps more important to me than it may be to those of you who play a druid in pve environments.

So, is there any firm equation with X avoidance = X% chance to avoid hits, or anything that could guide me in anyway.

The new Sof gear has it spread over several pieces.

So sadly you might have to get aug or two with it. TSS has group quest aug with 5 avoidance I believe. Nightmoon stone. And in Relic there is 5 avoidance 1 shielding 50hp mana aug.

Flametouch mask has 2 and do you have the diamond coldain aug fully done?

my tbs arms has 25!

Getting hit by anything of consequence in SoF (and I imagine the expansions after this) as a leather class is close to impossible to survive. I actually miss mobs hitting you less often and the changes they made to mob hit rating to reduce spike damage and make debuffs more revelant are very much plate favored. I have much higher than average AC and max avoidance, all but the SoF defensive AAs and dodge mods and I've been stun lock pummeled to death by two light blues in Fort Mech in a matter of 8 seconds.

Sad to say, but the way I see it the difference 31 avoidance will make for you is dying .01% less.