It's inarguable that the PAC12 was weak this year. That makes it really hard to assess Utah.
Utah is clearly better than they were to start the season. Rising is much better than Brewer and Tavion Thomas has turned into the engine at RB. Neither of them played substantially in the losses to BYU and SDSU.
That's not to excuse those losses (after all, coaches choose who to play) but to state that Utah is clearly a better team now than they were at the start. But it's hard to really say how much better and how good they are.
As you point out, the PAC12 has been weak, so it's a situation similar to BYU last year. Looking good (albeit not quite as good) against weak competition (albeit not quite as weak) leaves a lot of ambiguity about how good a team actually is. We've all watched enough that we can tell Utah has turned into at least a solid, above average team, but it's honestly tough to assess more, given everything