I think if you want to invest for the long term, it's better to still hold your ETH. Or if you want to have both, then you can exchange your 1.5 ETH with EOS.
But, why don't you want to exchange your ETH with BTC? if I have 3 ETH, I will exchange it for BTC
( just my opinion )Both altcoins are good in long term investment because it have a good developer and real product that can provide awesomw services.
For me I'm prefered to choose EOS because of their product that can surpas ethereum or even ripple in the future, but if you trust both project then go and hold this two.