Do all bidet seats reduce seat space?

[deanbrew]

I just spent a week in a vacation house that had a Toto Washlet bidet toilet seat, and I loved it. I'm seriously thinking about buying a bidet seat for our home toilet. But I didn't like how the bidet unit reduced the amount of seat area. It effectively pushed one forward, closer to the front of the toilet. Without getting graphic, I was a bit cramped, and uncomfortably close to the front edge of the bowl. This was on an elongated toilet, like I have at home, so I can't imagine how cramped one would be on a round bowl toilet.

Do all bidet seats reduce the available seat area, reducing the hole, so to speak? I can't seem to find dimensions on the manufacturer websites. They show overall dimensions, but not the actual seat dimensions.

Thanks, and I'll likely have other bidet seat questions as I look for what I want to buy.