Are you aware of FUSVX which has a lower e.r. than FUSEX?
Here is another link: ETFs vs mutual funds - Bogleheads
ETFs settle in T+3, mutual funds in T+1. This may have consequences if you wish to get cash out after selling: The ETF will take 2 days longer.
Dividends are paid a few days later, too, and your broker decides the price when automatically re-invested.
..., since long term I would consolidate in Vanguard and if you convert ETF->Fund, your cost basis stays
At Vanguard, one can convert some funds to ETFs, but one cannot convert ETFs to funds except by selling the ETF shares and buying the fund shares. Thus the cost basis does not stay the same.