I doubt that it does anything any differently, but it will probably feel "better". I've got both the Canon B and C angle finders and they can be useful at times, and they certainly help when you want a low angle.
I guess we're really talking about build quality / performance versus cost here? Many people are quite happy with a cheaper version. After all it's not something that you're using all the time, so if it doesn't feel so substantial so what? Others will pay a bit more for what they consider a better made product. I'm not saying any one is right here, just that we can see it differently.
If you're likely to make a lot of use of it then personally I'd go the Canon, even though the prices are ridiculous nowadays. If it's intermittent use then not to consider the cheaper alternatives would be silly.
cheers