Antminer S9 questions

[PointHope]

I'm looking seriously at doing a bit of mining.
The machine to get seems to be the  Antminer S9 from the reviews. Albiet has some reliability issues.

Some say this machine will generate .5 BTC every month, is this real or just a sales pitch?

Is there a thread which discusses the S9 ; general maintenance issues, what spare parts to keep on hand, ect?
What is the service life of such a miner?
Can you switch from BTC to another coin? Which ones?

[unholycactus]

It's probably more like 0.05BTC every month at the current difficulty.
It's less and less as time goes by.

[PointHope]

It's probably more like 0.05BTC every month at the current difficulty.
It's less and less as time goes by.

Still 0.05BTC is reasonable profit, means you pay for the miners in about 90 days.

That's what I'm hoping anyway, I'm in Thailand where electricity is slightly cheaper than the USA and hopefully the free trade agreement with China applies to these electronics.