Patient Reaper

Patient Reaper give 60% increased recovery of life. I interesting life leach, because with life regen and flasks all is simple. So question is what increased exactly? Max life leach from 20% life per second to 32% or default leache recovery rate from 2% to 3.2%. Or, for example, 2% life leech from Warlord's Mark?

Increased leech recovery rate does not increased the max leech rate, but it does help you to hit the max leech rate more quickly.

From the wiki, the formula for leech is:
recovery/s = (# of leech instances) * (maximum life * 2%) * (1 + %increased leech rate)
however this must not exceed the leech cap of 20% of max life per second (this cap can be raised).

So if you have Patient Reaper active, and no other modifiers to your leech rate, then each instance of leech will heal for 3.2% of your max life per second. Note that increases to leech rate don't cause you to leech more life overall, you just leech it more quickly.
So if you have 1.2% leech on gear and deal 1000 damage to two enemies, you'll have two instances of leech that each heal you for 12 life, but if you have Patient Reaper they'll heal you in 10/16 of the time.

For more info check the wiki, there are lots more examples on the leech page.