Dash and Ethereum are two totally different things. I would definitely buy and hold ETH because right now there is nothing else really like it and it has major potential. Dash is basically the elite's blockchain idea with them controlling 'Masternodes". Works great, but expect the 'masternodes' to add identification layers later.
evolution will remove the idea of masternodes with savings accounts, whereas any person with an evolution wallet can gain interest from the activity that current idea of masternodes performs