That's a very astute observation.  The difference is huge.  But essentially,
it's the only thing you have to go on right now.  If you ask 100 people
whether they like Orion speakers better than Polks, you'll get 40 who say
Polk, 40 who say Orion, and 20 who say they're both junk.

All I can tell you is that both are well-crafted.  I haven't heard any of
the newer Polk or newer Orion so I can't judge.  I used to love the older
Polk dB series from 7-10 years ago or so.  I'm not sure if they resurrected
the design or just the name.  Then they came out with that EX crap which
didn't impress me much.  I've never much liked Orion's speakers (though I
own an Orion amp), but I've been assured that they've recently revamped
their design.

Also, I've had good luck with both companies in terms of supporting their
products.