In my opinion both are good options to invest. Why not 50% Ethereum and 50% Dash?
Because Eth is the better bet? It's more stable, less chance of losing a good portion of your investment.
ETH is always better then dash as the volume of ETH is also bigger in compare to dash but there is not much movement in the price of ETH at a moment but if we manage to hold it for some more time then it can be an profitable decision to make and one thing is for sure that it won't disappear and will survive for a long time and I believe its an safe investment to make in ETH.