Originally posted by butangmucat IIRC I've read in the review that FA-1W has a smaller magnification. Is that a significant difference from the FA-1? FC-1 is quite pricy and I'm losing the hot shoe...
From this link, it looks like the FA-1W retains the hotshoe:
Pentax LX - Full Info on Its Interchangeable Viewfinders (it's the FA-2 which doesn't).
As mentioned, if your glasses are already corrected, the extra diopter adjustment shouldn't be needed, apart from more adjustment this seems to be the same as the FA-1. The FB-1/FC-1 combination has much reduced magnification, giving much greater eye-relief but it is a much smaller image. The FB-1/FD-1 doesn't have sufficient diopter adjustment and has limited eye-relief, but has around 1.0x magnification.
Another option might be a M series diopter frame with a prescription lens installed.