"Unlimited" is just a nice way to say limited by CPU/Process/Nodes it looks great on paper but its massively misleading generally it leads to overage bills or TOS suspensions
Keep a eye on the changes to the algorithms that mite effect your SEO or the way you approach it I know there has been alot of change recently
https://moz.com/google-algorithm-change
I tried Firefox OS, Somewhat slugish and Ubuntu Phone OS was murder on the Nexus 4..
Hopefully the stability will improve once they get a little more age behind them