I have one. It didn't quite fit right, so I emailed the company for help [i was fitting it out of normal business hours], received a phone call the next day, they sent me a modified component the day after. Excellent service.
I'm very happy with it, it certainly serves it's purpose. You do have to consider how to secure the sliding door when fitted because you lose the use of the lock. I have heavy duty sliding door locks top & bottom [1 type is included with the panel]. We bought white to match our door, it looks good.
The price did vary quite a bit between different sellers, Bunnings wasn't the cheapest.
Edit: It's great for me because I have 2 sliding doors side by side, one in regular use, the other has the PIM door permanently in-situ with the locks hard set. I do think it would be difficult to use the PIM in a door you use regularly because it restricts the available opening & be extra hassle to lock/unlock.