This is a decision you will make. I hold some mining power there for a very very long time and it never failed to pay. I made my ROI and took out 40x the initial investment.
When their former power supplier pulled off the plug last month, I got very worried, esp. after seeing all that has happened with mining related sites. With one difference: the admin came right away in chat and explained everything. So, I made the decision not to sell my share but exactly the opposite, invest more. Many people panicked and started selling at ridiculously low prices. I managed to buy 4x the share I had back then, at the 1/3 of current price. I only watched out for one thing, not invest more than I have actually withdrew over time from this site.
It proved to be a right decision so far.
Play - but play safe.