Could a few Pathfinder players and DMs please share their thoughts on Mythic Adventures?
Is it a good thing? A bad thing?
I haven't seen the "Mythic Adventures" rules yet. My gut feeling is that running Mythic advancement in parallel with the normal level range is probably a better solution than 3e's Epic levels. But I'm also pretty sure that it's not for me.
Does Paizo publishing Mythic Adventure Paths lessen their usefulness to you if you're not using the Mythic rules system?
Almost certainly, yes. What I've seen of the "Wrath of the Righteous" path gives me the distinct impression that I can use the Mythic rules (either from the book or the SRD), or I can forget about running the path - the adaptation would just be too much work.
As it happened, I was probably never going to run WotR anyway (I haven't run any path so far), but still - there's a difference between
choosing not to run a path, and feeling that I'm
unable to run a path.
At the moment, I'm in a "wait and see" mode. If the Mythic rules become a fixture of paths going forward, I'll almost certainly cancel my subscription this time next year. If this is a one-off, or they're used sparingly, then I'll stay on board.
(Of course, it also doesn't help that I was really underwhelmed by the previous path. I liked the concept, and especially liked that they were willing to take risks with "Rasputin Must Die!", but when it came down to it all six adventures in the path were just "find the McGuffin" railroads, which was disappointing. WotR, thus far, seems much more open, and that's a good thing... it's just a shame I can't use it!)