I've worked in startups and big companies. Currently at a startup.
Wardrobe means nothing. Heck, if you're using a wardrobe as a benchmark of trustability, RUN from the guys in the suits. This is based on experience.
Viability is an important concern. Companies do go belly up. Certainly don't put everything with one of these firms. But most importantly, research the fiduciary aspects. While I haven't researched it myself, my understanding is that all shares are held with a custodian in a segregated account. You would get this back if they went belly-up. It just might take some time.
I'm actually trying the Schwab Intelligent portfolios with one of my IRA's (~15% of my retirement accounts) to see how it works. I've researched the options, and I trust Schwab's methodology best. Bottom line, I think there are some things a computer can do better than a human, and some things humans can do better than computers. I trust that a computer can optimize a Sharpe ratio better than my spreadsheets can. I also think that the psychology of having a managed investment account may prevent emotional investment decision making. We will see if this turns out to be true over time.