440s are solid cup. I think I like the 508s more.
I've not skated the 508s yet but coming off the 440s, the 508s feel like they're hugging every portion of your foot, the 440s, while great, just felt average (and very flat) and nowhere near the level of padding compared to the 508. Plus, I got the all white 440 leather, felt like I was wearing the dad version of a NB skate shoe.
The 440s run bigger all around than the 508s, not sizing per say, just overall fit, just a but roomier. Again, the 508s, like the 1010s, are snug/slightly bulky; there's a lot of shoe going on.
If I had to sum it up, the 508 feels like a real 'sneaker' from the 90s whereas the 440 and 255/306/272 feel like a modern/generic (albeit great) 'skate' shoe (i.e. not much going on).
The blk/red/white 508s are pretty bad ass looking as well!