Regarding your extra funds that need to be allocated somewhere, my personal choice was to put most of mine into
Betterment. After reading about Betterment in several places (
MMM,
JohnnyMoneyseed ,
JLCollins, among others) and doing additional research, I decided to open an account and haven't looked back since.
It's simple to sign up, they have a great interface, management fees are low (0.15% with over $100k invested), no trading fees, automatic rebalancing with every deposit, tax loss harvesting with over $50k invested and best of all, almost all the investments are made in low-cost Vanguard index funds. Additionally, at the time I signed up they were offering free trial periods based on your initial investment. I actually had an issue with this because I had used an affiliate link and they didn't correctly combine the free periods but a very quick phone call with a very friendly support person took care of that.
Of course you could continue to maintain an account somewhere else doing your own rebalancing and tax loss harvesting, but it's hard to beat 0.15% fees to have all of this done automatically.
So far I've been very please and I'm confident that I will be sticking with Betterment for the long term.