Maybe I was doing something wrong on Nanopool, but for the 6 hours I mined, I got 76 Sia. Does it catch up over time because it is PPS? Doing the math, I still think Eth + Sia is the most profitable combination right now. Anyone disagree?

As for Ethereum difficulty, I guess as long as the price keeps going up it is still worth it to mine. On 4/25 one ETH was worth $49.94. It took me 12 hours to mine .1 ETH so, $0.41 per hour earnings (ignoring cost of electricity). Today one ETH is worth $228.64. It took me 21 hours to mine .1 so, $1.08 per hour earnings.