Fitted the PR433-4 today and it works a treat. Wired between the COM and IMP on my ASNA roller door. Took a few attempts to teach/train the PR433-4, but got there in the end. I think this was just down to me being slightly out of range (during test fit) and being a little slow between the car and module. Once I moved the car and module it was fine.
I used the TEST function first to ensure the roller door would react to the module (and that I had wired it correctly), then programmed the car.
Worth £75? Time will tell. Suppose depends how long I keep a Homelink enabled car... We don't park in the garage, however use it as one of the main accesses to the house with food shopping or pushchair etc.