Your calculator isn't probably very accurate because as I increase the range, at some point it fails to show your and their statistics.
Your house edge looks really attractive not only for small betters but even for those who bet high because the house edge only grows when you really bet a lot and increase payout.
By the way, your website and the other two ones are looking very much alike. What about to change user interface? I don't know what others think but to my mind, it's not attractive and makes me wonder which website do I really visit. I mean, I think you need a brand identity and some visual uniqueness.