Wistia customer here (correct url: http://wistia.com). I haven't used any of the other products listed here (it's the first time I've heard of any of them), but I will say that Wistia has a nice clean player, awesome web app, and amazing customer service.
SproutVideo's pricing model seems a little mis-aligned in the space with Vidyard and Vimeo Pro. Half the bandwidth for double the price? If you know anything about bandwidth, $1/GB seems excessive.
VidYard and Vimeo Pro are both incredibly new offerings. If you look at just about every single established player you'll see that they have very similar pricing models to SproutVideo. VidYard and Vimeo Pro's pricing models seem to be based on the assumption that the majority of their users will not use that much bandwidth.