Got my CAL! in tonight. I have to say, I'm rather impressed with it. For the price, these are a very very good sounding headphone. Yes, they feel super cheap (seriously, I'm terrified to put these in my messenger back for the ride to work tomorrow!). Yes, the cord is terrible (super thin, super short, non-removable). Yes, they're a very small over-ear (kinda weird but not uncomfortable). But it doesn't matter because the sound is very good.
Bass is on the heavy side without being over the top or too loose. The bass blends in with the mids very well and the mids sound really really good. The weak spot is the trebles, which sound severely rolled-off. The overall sound is slightly warm but not a ton. The soundstage isn't half bad for a closed can, too. These are just a really nice all-arounder that's easy to drive and cheap.
I'm going to have to get my HP100 back from the wife to A/B these. Just from memory, the HP100 already wins in build quality and comfort. I can also say already that it has bass extension on these and a much more neutral sound (sub-bass hump instead of mid-bass). But I want to listen back to back to hear how much of a difference there really is overall. The CAL! is so much cheaper than even the refurbished HP100 that it could be my new go-to for a cheap closed all-arounder.
For $50, this was quite a bargain! Thanks to whomever posted that deal!