Since they changed to using webkit, they are, in my opinion, basically irrelevant now.
Since most people don't care about the engine, this is clearly not true. If more sites work they are more likely to get more users, and that makes them more relevant than before.
Say what you will about Presto not working on site x, y, or z, more diversity is good, and it helps keep real standard in check.
Yeah, but who is going to pay for it? They spent insane amounts of money trying to catch up with other engines.