I love vans pro skip-ons, but two issues
Being vegetarian, I get the canvas, which stretches out almost a half size after wearing in, but at the beginning a half-size smaller might be too tight with regular socks.
The heel cup. Same heel cup as on a standard-slip on, which is perfect for me, but the thick ultracush insoles makes your heel ride high and puts it out of place, until you wear them in and pack the insole down a bit.
Also have some consolidated slip-ons in waiting, which seem sturdier, but no cushioning around the ankle bone. Curious about those.