If you are limber, not to big, do not mind being confined on a long drive with barely any room to move around, add in the cost of mounts, sliders, losing seat air bags(not always a bad thing but can be) etc......I have had many race seats, all real ones, some sold as race seats that were horrible, some great ones.....really not that fun to live with especially if you get in and out of the car quite a bit on errands.
You would also want more expensive Sparco seats, I prefer Recaro, better yet Racetech but they do not make anything but full race so very snug.
I have really good air bladders for lumbar adjustment and top notch seat heaters, neither weighs all that much. I looked into a fixed seat swap and in the end it would of saved around 14lbs in the middle of the car, most weight down low, not the most important place to loose weight and I knew it would be less comfortable than the stock Recaro seats, a lot less comfortable overall.
Sure look cool though, I have to admit that