Any device you take to certain locations will be compromised. Regardless of device choice I would recommend not using internet banking etc. and set up travel accounts for social media
Woah now I feel careless for simply taking my iPhone for my around the world trip... what exactly is the threat you guys are preparing against? I'd mostly be concerned with ATM scams.
I mean I'd probably be way more concerned if going to the US because of all the security theatre, but Asia is so safe for tourists in comparison with (South-, Central- and North-) America and Africa that I wouldn't bother getting a separate phone. If you go to China, buy an iPhone (for maps and facetime) and make sure your VPN works and routes all traffic before hand because Google doesn't work. If you go to a country with Muslim regions, don't forget that there might be weird bans there (reddit doesn't work without VPN in indonesia, wikipedia doesn't work in some of the arab countries, most African countries have Arab telcom providers and those enforce Arab law there too, ...).