The "racing" seats are hard and minimally padded for a reason.

The seat should push only on the sit bones in your rear, a cushy seat like that may be fine for shorter rides <20mi but on longer rides the padding will push up between the sit bones in your butt and cause some painful pressure.

The hard seats may hurt your butt for awhile but you just need to get used to it. As the muscles in that area start to get in-shape the seat won't hurt anymore and will eventually be fairly comfortable.