Indeed, when comparing ubuntu's mobile os running on a galaxy nexus with firefox os running on very cheap hardware, you should expect a difference.
I would be interested in seing how ubuntu mobile runs on a 69 euro phone.
Yeah, I'd be curious to see that too. However, end users don't usually care about hardware specs directly, they care about the end experience. And if you're pushing for a new platform right now, you have to really try and build an ecosystem around it as soon as possible by earning enough fans and developers to keep the platform sustainable. And as developers, I know we like to think we're rather objective about a technology's 'true' merits, but UX impacts our decisions too. So if Ubuntu ships their OS on hardware that will provide a better experience than any FFOS phone out there, Imma place my bets on the OS that shipped with the better overall UX out the gate (even if it's not as cheap initially). I mean, it's not like we didn't already see this partially play out with WebOS. Even Windows phones are struggling and they seem to have a really nice UX...