Butterfly on Lifestealer

Today I tried Butterfly on naix with stout results, odd game, they picked pudge so I went mid against him. Ended up first blooding him fairly fast and had a decent game, my farm was good and it ended pretty quickly. The thought process began with not going SnY because I had the good to go for bigger items and wasn't really being stopped. So by 18min I had phase-armlet-desolator, than progressed into Basher-butterfly-abyssal. The evasion made it easy as hell to keep myself healed, while the added attack speed and armor from the agility added their own advantages.
Normally I wouldn't do this but it made sense after the game was over, but normally an assault cuirass would've been my go too, just interesting the benefits butterfly gives the hero. Thoughts?

The maths on this are pretty tricky, there are too many variables to give a definite answer on how this stacks up against either Assault Cuirass or Heaven's Halberd. What I would say is that value for money wise Heaven's Halberd is better for strength heroes, but when you're 6 slotted that's less of a factor.

However, there isn't much doubt that Assault Cuirass will generally offer you more DPS due to the greater attack speed boost and armour reduction. The evasion on Butterfly is very strong, but becomes much less impactful when there are Monkey King Bar's floating around on the other team.

I think under the circumstances you describe the choice didn't really matter too much, and generally I would favour the other two items over Butterfly on strength heroes.

DOTABuff links provide a bit of information, such as what Heroes and Items they had on the other team *hint hint*.

But if they had no good MKB Carriers, I can see Butterfly causing more trouble for them than Heaven's Halberd. Not too sure if Butterfly is better than Assault Cuirass though, since it does provide the Minus Armour to your opponents and +Armour to your Team.

I think it works as more of a suprise factor, it's not a hero you'd generally get an mkb to counter

If you already have an AC carrier or you alreadly have it yourself, and no opponents have MKB its a good item. I would always get abbyssal and any other items like MKB you might need first though. But it is a good 6th item.

AC and butterfly are very comparable, but AC should be concidered first on strength heroes and butterfly concidered first on AGI heroes.

Butterfly is really strong on Naix or Alchemist for that matter. They profit heavily from the 60 IAS and the Evasion is also pretty good.
AC is still better for pushing and to support your whole team.

DPS- wise Butterfly is better than Halberd on pretty much every hero in the game i would say. But you get HH mainly for the Disarm anyway.

An AC is ALWAYS better

Dagon is the best surpise Item on Lifestealer. They expect the 10:00 Infest, but they never see the Dagon coming! 8{D