I came to a similar conclusion, casper will be a oportunity for other chains to increase their hash rate as miners shift, but does not mean they will go for etc. another thing is how i keep reading that eth is not a money, its not meant to store value but to be the first layer of the network. Im holding both coins, more import is to make as much eth as you can right now, so your in a good positiong when PoS starts.