As you'll see from my TalkMorgan name I went for a MOG number plate, as have many Mog owners. Can't really justify why, just thought it was a bit of fun.
Many years ago I bought a personal number plate for my tin top, my initials + 3, it would now be silly money, probably now go for a 5 digit amount, so could have been a good investment? It does make it easy to remember my number though, especially as the years take their toll of the brain cells!
My advice is - if you fancy it, go for it.