I bought this years ago. This is kind of a one packaging for a few. The model I bought is the PT-04GY depicted on the upper right corner of the above picture.
I have used this with my cameras and flashes and they all work pretty well together, which is a good surprise. The battery inside the transmitter still goes on and on after years of occasional usage. I even connect it to my Hasselblad, or actually the Zeiss lens' PC plug to trigger the flash with no problem. Just make sure the battery doors are properly closed and maintain good contact and the channel is the same across the board.
I don't know how reliable or unreliable are others. For me this setup serves my very basic fundamental need for flash photos.
Unless I want to get into off camera flash using a higher than sync speed then I really don't see any compelling reason to upgrade.
Flash at a shutter speed higher than the X-sync speed is a topic that continues to confuse and confound plenty of users. I've seen an Youtuber who totally got everything backward and yet appears totally authoritative. When you have that level of confidence, you can do anything you want and achieve world dominance.
In the interest of the general public I shall refrain from talking about flash X-sync.
