For a long time now i've been using LpSS as my main form of life sustain. Long story short, i've always been a rather poor fella and when i started playing it seemed to me that the best compromise when it came to budget/DPS was to ignore costier sustains such as LoH (back in the days of 1.03, LS was hardly considered viable and then only to the highest DPS'ers). Indeed, weapons and helms with LpSS seemed to cost MUCH less than their mainstream LoH counter parts. This still holds true as i am writting this guide and is one of the big factors that drove me to share my view on LpSS.
First-hand i'd like to answer some of the concerns/questions that are always thrown to my face whenever i try to make the eulogy of LpSS.
-But Fuzzy, does LpSS ON ITS OWN do as good a job at generating HP as the other options?!
The answer is, dependingly on your build, yes it will. So long as your monk has 2APS and a decent base of crit chance, Quickening will fuel you all the spirit you need. At 2APS, i've calculated that 200 LpSS will generate between 6500-11k HP per 1-2 seconds.
What should be noted here is that the most efficient way to use LpSS IMO has always been to couple it with 2-3% of LS once you've reached sufficiently high DPS.
-What about the sacrifices in slots and DPS i make in order to use LPSS?
I've heard that argument a great many times as the fear of losing DPS is always omnipresent. The truth is, if you do it right the only thing you'll lose from focusing on LpSS is ONE weapon affix slot (since you'll need a weapon that has BOTH LpSS and LS as well as a socket and natural crit damage) and the capacity of using Mempo over Inna's and that's only in the case of focusing. I've seen a handfull of monks who were using lower amounts of LpSS as a complementary stat and who were absolutely in love with the extra burst heal sustain it provided.
-What MP can it handle ?
AFAIK, as high as your other stats can take you. It's all a matter of being at a level that's manageable eHP and DPS-wise. For me that's MP6 on farming and MP8 on ubers. If i had 125k-150k DPS and 500-600k eHP, i'd probly be going on higher MP. All in all, i dont believe LpSS is in any case an impediment to MP progression.
Now as to the guide itself!
What's LpSS ? How does it work? Well basically, you generate spirit and then use that spirit as fast as possible in order to generate HP in real-time. For each point of spirit spent, you will gain an amount of life equal to your total LpSS value. From that we can deduce a couple of things:
1) ALL YOUR SPIRIT SPENDERS HAVE AN ADDED BURST HEAL EFFECT! AWESOMESAUCEZ! :P
2) LpSS only scales with itself (more LpSS) and with attack speed/spirit generation speed (high attack speed or high spirit regen builds).
3) The higher the cost of the spirit spender, the more HP you'll generate.
4) You'll be forced to use fist weapons and fore-go all the other weapon types.
Lets start with the items and skills that are beneficial to a LpSS build!
Unlike other life sustains like LoH and LpS (not LS though), LpSS takes very few affix slots in a build. LoH for example, as popular as it is, would take a slot on each of your weapons as well as on each of your jewels and possibly your pants (blackthorn pants). That's 6 affix slots dedicated to LoH. In comparison, LpSS only requires 3 (both weapons and helm).
1) Inna's Helm (with 50-60 LpSS) - An absolute MUST if you're intent on making LpSS your primary form of sustain.
2) Won Khim Lau (with 50-60 LpSS) - This is one of the beauties of the build; you can find WKL's in the 900+ DPS range with socket and maxed LPSS for about 10-20M gold MAX and some are even cheaper than that. As most of you already know, the Skill Damage bonus and %Ele Dmg bonus add a lot of eDPS, making WKL one of the best (if not the best) monk weapon.
3) Rare fist weapon with the following stats : 50-60LpSS, 2-3%Lifesteal, 60%-100% Crit damage and an open socket (if you're lucky you can find one with all these stats AND some DEX) - This right here is the cherry on top of the cake, Lifesteal actually becomes your SECONDARY life sustain stat. This is very important as it basically makes you impossible to kill if you just play smart. Using PURELY LpSS without any Lifesteal is very challenging at higher MP levels. It's possible to do but i will always recommend picking up some lifesteal at some point.