The Sargent seat and cover look great, is comfortable, and installation was quite easy. Somehow I wasn't aware that you're not purchasing a new rear seat, but rather a cover. Not that it presented an issue, but just FYI.
This is the single best upgrade (perhaps other than some sticky tires) to the ZRX that you can make in my opinion. I have changed, added, and upgraded a lot of things to my bike over the years, but this Sargent Seat is the best thing I've done to it yet. This seat is light and even adds some waterproof security for important papers! Very comfortable for distance riding. It allows you sit to further away from the tank very easily if that's your style.
I bought this seat because my wife wanted a more comfortable pillion seat. Unfortunately, it doesn't really improve on the standard seat in this regard, and I find the riders seat is much higher than the original, making it uncomfortable for me when stopped because it's now a tip toes stance, and also while riding because it shifts more weight onto my wrists. I suspect I may have the lower version of the original seat. So it's back to the old seat for me and try to sell on this one. The seat does seem to be well made and looks nice though, but doesn't completely fit the tank recess.
This seat is slightly wider than a stock seat so you may find the need to use a lower position. Give it a few hundred miles before passing judgement on its comfort. When I first purchased it I was ready to send it back after one day. Now, with just over 500 miles on the seat, it feels very comfortable. Good news for those who ride two-up. My wife reports that the rear portion of the seat is very comfortable.