I own four various models. Two 4003's, a 5903 and a 4563. One of the 40's and both the nine and 45 have rails. I can live without the rails, but it didn't stop me from buying them. The fit and finish is better, IMO. The slide and frame are mated from the beginning to the end of the production line, insuring a superior fit. They have a loaded chamber indicator, night sights and are the last of the 3rd gens. Fully loaded, they weigh a bit more than a Glock. They are usually considered the best, save for the Performance Center variants. Do not hesitate to make the trade. You will enjoy it.