My experience is that they usually complicate your taxes. In particular, past a certain asset threshold, Wealthfront will do something called "direct indexing", which basically invests your money in individual stocks the way an ETF would. It has TLH benefits, but at the cost of a massive 1099-B that you have to deal with every year.
> Wealthfront has a turbotax import option. You tax accountant can press it too
Two issues: complexity of return and efficiency of turning pre-tax into post-tax income. Wealthfront is good at the former. It's half decent at the latter for moderate income levels. Above some threshold between $500k and $2mm, it's not the best.