I'm pretty sure i'd like to dip my fingers into twin engine and IMC as a minimum at some point during my life.
That pretty much answers your own question - PPL good luck with it all
It's likely that at some point my flying will gravitate to affordable LAA types where an NPPL would be fine.
However as a relatively new PPL, Night Qualification was great fun and I'm looking towards the IMCr, it's all about getting good quality training and improving my own standards right now. A raw PPL/NPPL doesn't actually inspire one with a great deal of confidence to fly off into the sunset to be honest, so it is wise to look beyond the basic licence. As you already are doing that, you might as well do the PPL. I have a Class 2 medical, most people can get one, if you have a problem that would prevent it, chances are you already know about it. The only real advantage I can see of an NPPL is as has been said, you can't for some reason get a Class 2 medical.