I do wish the one I have would be larger. They walk around it some. It improved the problem, not eliminate it.
I like the 2 piece blue one you found better. It has the tray underneath that I like on my smaller one. You just tip the tray carefully over the gargabe bag any the litter drains out.
And when are the manufacturers going to learn use less obtrusive colors. How about a nice neutral grey that does not clash with my decor?