I think that if you are going to invest in bitcoin, then you should actively be using bitcoin. Through your experience in both mining and making purchases with bitcoin, you will be able to make a determination on whether bitcoin is for you.
I think what you will find is that the bitcoin is a strong currency, and is the way of the future........unless you like fiat currency, fractional reserve banking practices, and having your currency affected by variables from which you have no control over. Invest now.....just don't put everything in bitcoin.