I would love other payment methods like litecoin, zcash or dash.

Simply because BTC is awfully slow and for ETH most of the exchanges requires that you have 0.1 or 0.2 in your account before it's credited to your account which makes it less compelling.

I can use a local wallet for ETH but I can't trade it right away for other altcoins on exchanges because of the 0.1/0.2 limitation on most.