Ian, I'd say two things...
Firstly, I prefer Morgans with the vinyl plate on the wing, rather than the centrally mounted plate on a plinth. In going this route, I personally think the portrait style (square) plate tends to look better with five or six digits. This brought me to MOG because whilst you can have five/six random characters have the bottom, or top, line reading MOG just looks aesthetically pleasing to me. The other option is TOK but this isn't as relevant but the argument I posed above does stand for it.
The second point is that I personally like a plate that means something to me and most people probably wouldn't 'get' (obviously MOG isn't that). I have a plate that is just that style, which was on my Red and Black two-tone Roadster, that always used to make me smile but I think many people wouldn't make the logical jump as to the meaning. I have a similar plate in mind if a MOG one doesn't come up and again, it is a vague reference but not blatantly obvious. However, in both cases (my existing plate or the one I like but haven't bought from the DVLA), they don't suit the vinyl wing mounting and need to be in-line on a regular style plate.
As for personalised registrations as a whole, my view, as with most things is: each to their own. Your car, if it makes you happy, spend your money how you see fit.
