Not good if you're invest with eth at this moment, the price too high. Many people choose eth as investment just because the price but they don't remember the price can also falling down. I suggest wait eth until the price below 0,1 and then you can buy it. Maybe you can buy another coins like ripple or monero as long time investment. Good luck.
Ethereum is excellent for long-term, some markets and wallets also start using eth for transaction fees purposes and will automatically impact on increasing demand. This coin is good for investment and the best time to buy eth is nowadays because the price is not so expensive.
The bottom of the etherium will be below $ 90, it will be during this year. How can a long-term investment work, if the etherium is mined more and more, this is not logical ...