For me, having its value on a spike or the quality of being highly volatile is still the better option for me, having this quality means I would be able to play may money and earn profit on my own. Having a steady growth is fine as well, and I can see many investors being happy with it, but I would choose the highly volatile bitcoin.
People must understand the fact that bitcoin is volatile, and it happens to be powerful source just because of this one feature. Remove this one nature of bitcoin and see the clumsy results.