Having owned the Exile Pros, they make a good speaker at a good price. Exile is a startup by former Phoenix Gold employees that left when PG went to shit. I think I prefer the Alpine tweet, however, but they're both very good, so it depends on price. (Also, the Exiles might be easier to fit as the brand tends to be very conscious about mounting depths, sizing issues.) The Alpine is just a very musical speaker. Doesn't "stand out" in any regard, but that's the best thing about them, I think.
Hertz is just starting to get some notice in the U.S. They are the speaker division of the company that makes Audison amps. Haven't yet heard them, but have no reason to think they'd be anything but great. I read on some Australian boards, where the brand has been available a bit longer than in the states, that the HSK tweeter was a bit harsh for some. But, I've never heard these myself so take that with a grain of salt. Their Mille sets look amazing, though, and the Space sets look like they'd be a great option for someone with limited mounting depth.
Never been a fan of Polk, but I suppose you could do worse. If you've heard them and like them, trust your ears.
It's not an option always, but it's really worth it to listen (yes, even off deck power, even on a board) to everything. You can't always trust it, but at least it gives you an idea of what you're looking at.