The medical is simpler as it can be provided by your GP rather than full Class 2 medical from an AME.
I'm not sure of the differences in the training but post licence entitlements are not so many. I do not believe you would be able to use your licence abroad (since it is not a JAA but a national licence), you can't "upgrade" to subsequent licences or ratings or use it as the first step in the modular scheme for a commercial licence.
So, if you think you may want to do more with your licence, I would recommend a JAA PPL.
Cheers
Whirls