Both virtual currencies are good for investment and the only difference is their price. Bitcoin is already proven as a good choice for investment, whether it's short or long term but it price is higher than ethereum. Ethereum, on the other hand, is still new if you compare to bitcoin but its platform is promising. It still cheaper if you compare to the price of bitcoin and you can still afford to buy 1 whole eth. Ethereum has already shown in the past that it can make its own bullrun.