It's definitely scary to do that right now, I had the option to pick up some more ETH early today when BTC was still above $1200 but decided for a more stable investment (basically turned it to fiat). It's called taking profits from Bitcoin too, this was another peak and I doubt we'll see it again in the next months.
I hope Bitcoin get it together eventually (honestly I don't know how for the reasons I mentioned many times in this thread). You used the word complacency and that's exactly what happened in Bitcoin lately. Today I've read that Google was the 21 search engine in history. The self fulfilling prophecy that Bitcoin is Myspace can become a reality if this trend continues.
It's not so scary for me. I bought previously around 0.02. This is a top-up so that I feel I've a reasonable insurance against ETH overtaking Bitcoin. I have tons of reserves for a dump, but it's difficult to know when it will come - these exponential trends can really run away. Now we've sailed past the ATH, I think even 0.1 could be on the table.
I honestly don't think in BTC price terms anymore since I'm completely out of it for the moment. I may buy again when the situation clarifies but the price will most likely be below 1k and then some. I bought some Factom last week and like most top alts it has been performing great both in fiat and btc pairs.
As for Ethereum, Metropolis is coming in June, I don't think this kind of daily appreciation rate is sustainable however as you said, this can go very high, more than $100 in the next weeks or month without a doubt, there's no reason to think otherwise unless something unexpected happens, fundamentals are there and I'm sure there is plenty of institutional money.
Volume and buy support is through the roof, I'm not selling a single Ether yet and it will be very hard to do when the time comes.
Those fundamentals that we saw are somehow strong that ETH would really have the potential to increase its price unexpectedly that's why its wise to buy it now since the price is still affordable if you wont take the risk you wont profit nothing at all.We are really doing the waiting game as of now.