Ethereum has its own problems, such as clogged networks after an ICO which severely limits usage.

As far as Bitcoin goes, the nature of its rallies tend to lend it to corrections after they're concluded. I don't think we're at one of those junctions now, at least the charts don't seem that way.

The bottom line is that Bitcoin has had general growth and so have other alt-coins. I think this is the crypto-currency golden age, where money is invested in all kinds of coins and there will be many opportunities for wealth creation.