On March 10, Russian media watchdog Roskomnadzor went on the offensive against Twitter, declaring that it will slow down traffic after network's refusal to delete tweets over thousands of requests. The "slowdown" affected large segments of the Internet for Russians - just like three years ago, when Roskomnadzor attempted to ban Telegram messaging app.
This time the problem was trivial: the system searched 't.co' in links without any additional parameters which led to 'slowdowns' of rt.com, reddit.com, microsoft.com, etc.
Depends on the model, but yes, the battery life will suffer. Also, you may encounter problems with minor features (color profile, brightness&sound keys, remote, etc.), however you can research all that info beforehand.
I am using Ubuntu 11.10 on a 5 yrs. old Macbook Pro and after some tweaking it runs just fine (I use it primarily as a desktop replacement, so battery life is not all that important to me)
(Link in Russian)