O frame = flat lense/closer to aframe fit
Crowbar/splice = spherical lense/fit pretty much the same but splice gives a larger down angle view.
If you wear a helmet, go in with your helmet and make sure goggles fit with helmet and your peripheral is good, and of course that they fit your face well. No helmet? Which one is the most comfortable?
As far as lens tint goes, if you are looking for an everything lens, 60 - 40% won't be great on pow days, may cause eye strain 8 hours on a sunny day, but it's better than wearing a hi-yellow for 8 hours at 12000 ft with nothing but sun....
I actually really like the blue iridium in that most days are sunny/partly cloudy and when the sun starts setting and there are lots of shadows, I can still see pretty well. 30% is enough for my eyes to not be bothered on a sunny day. But we're talking about my eyes, not yours. I usually stick to a 30% or 70/80. My other lenses just sort of sit around. Also look at stuff through the lenses. Like the color of stuff through the gold iridium freaks me out.
That being said, I like the aframes with blue iridium and hi persimmon yellow. Those are the 2 that meet my needs the best. But I'm not you.