I will invest in Bitcoin and altcoin at the same time but the money earnmark for bitcoin will be higher! Crypto currency is unlike firex that you can predict certain pair against other! Crypto is more dynamic and you may not understand what is driving a price of a coin!
Altcoins will take time but 100% profit. you want to earn money fast then invest in bitcoins but you have to put high amount here.
Some may even give you more than 100% in the long run. I have seen some Alts that have done pretty well in a short while and even ETH had a huge increase more than Bitcoin this year. The only thing like you said is that they take time.
Since ETH increase, it has been finding it hard to break past until recently and it is still back to the previous position it was before now. For trading though, I have been having some good time with it.