Health Regen vs. Lifesteal

What is the basis for whether a hero should purchase straight health regeneration vs lifesteal? Is this action based upon your hero's abilities, type (support, carry, ganker, etc.), item build, or just your play style?

I kinda already have my opinion on this, but I thought it would be beneficial to open this topic up to the community.

Usually,I pick lifesteal for any autoattack based carry(except outworld devourer and Storm Spirit)-(that is usually only AGI carries).

I get regen on heroes that don't rely that much on autoattacks,but they also rely on their skills,when things like Bottle work execently on them.However,there are a few case of hybrids,like Bounty Hunter,where I get both.

Basically what the above poster said. Any hero that punches creeps a lot will usually find lifesteal better. Otherwise you can probably lean toward regen.

Another question is health pool vs regen vs lifesteal. Lifesteal requires you dish out plenty of attack damage or it's wasted. Regen is basically good for farming/sustain but doesn't do much for you in a team fight. A big health pool, good damage and lifesteal is the ideal combination for fighting. If you can only afford one of these (say you're a support), I'd go for health pool.

Also Black King Bar is a usual choice with lifesteal - if you're not attacking, you're not healing.

The only reliable regen IMO is the one from Heart of Tarrasque and skills like Shadow Dance or Living Armor, so there is nothing to choose between lifesteal or regen, lifesteal is always better.

Not true, not true. You could say that those are the only reliable regen IN BATTLE. Weaving in and out of battle, yes those skills will be invaluable. However, regen is a reliable fallback in a number of cases. Take for example the solo lane Phantom Lancer. Tranquil Boots are a common sight, as are Soul Ring's. It really depends where you need the health, in battle or out.
Also, a Vanguard or Hood of Defiance is much more useful on someone like Axe than a Vladmir's Offering. Per given example, oftentimes the regen items give you useful additional benefits that lifesteal items will not. Anyone who isn't doing a lot of physical damage or a lot of attacks could benefit greatly from regen. It keeps you in lane, in siege, in battle much longer.

Yep it's true, I just think that mid/late game if you need any kind of hp restoration lifesteal takes priority over regen, cause that's the moment where team fights/ganks occur and regen will give you nothing in that 5-10 seconds of battle, when lifesteal can let you survive if your dmg is high enough. Also even if some of heroes can't benefit from lifesteal, you still don't build them into regen, just some for early game survivability. Regen should be just bonus to your build, I guess there isn't any straight regen build.

agreed. Regen is better in the laning phase while lifesteal is better in teamfight-situations as it provides somewhat of a healing"burst".

1 other thing to mention, is that most lifesteal items are damage-oriented while regen usually is combined with defensive stats.

The great exception here is Helm of the Dominator. I dont really like lifesteal items in general (i dont know why), but i am a big fan of this item. It gives +DMG +Armor , quite much lifesteal and its active can also be very useful (i always stack ancients with it, while farming somewhere else).

Also, lifesteal vs regen is a very hero dependent choice --> some heroes are just to dependent on a certain orb effect, that lifesteal isnt an option anymore (one can always argue with saying that Vladimir's Offering isnt a orb, but that item can be bought from any1 in ur team anyway).