One of the other reasons that I'd moved some bitcoin into altcoin was to attempt to spend or send it. With the high fees and slow transactions that bitcoin offers, it has become useless for small value transactions.

ETH works as a transfer mechanism, but as a currency replacement for online transactions it's adoption is likely to be slower. I asked one retailer about their plans for alt-coin adoption (ETH, LTC, BCH, BTG) said they were planning Litecoin adoption in short order (~weeks), not planning to adopt BCH, and on ETH:

"Litecoin is basically bitcoin's code so this integration is very simple, however ETH would need a complete rewrite and not possible at this time."

You can probably argue that the use case for ETH is not a currency, but because it is different enough from a number of other alt-coins, more infrastructure will be required for retailers to adopt it, should they want to.