I have my money approximately equally split between ETFs and mutual funds, and I gotta say: mutual funds are waaayyy better.
-ETFs lose money to bid/ask spreads and usually NAV at every transaction, so they are more expensive than a mutual fund with the same expense ratio
-ETFs should be purchased/sold 9 am to 4 pm Eastern time, which might mean you can't get to them for several weeks due to work, holiday, illness, life
-To avoid stupid market tricks you need to use limit orders which takes work, and sometimes the market runs the other way so you are unable to buy/sell at the price you wanted, which means you need to repeat the order the next day at a worse price
-If the market is doing something extraordinarily dumb while you are trying to make a transaction, a fund manager will likely be able to execute it more efficiently
-ETFs require each buy or sell to be a conscious, deliberate decision requiring at least a basic calculation (# of shares) which vastly increases the chances of doing something stupid or second guessing
-Regular purchases need frequent interaction and keep investing on your mind at all times, which vastly increases the chances of doing something stupid or second guessing
-Because of the above, investors in Vanguard ETFs realize returns an average of 1.6% lower than investors in Vanguard mutual funds (because of investor stupidity and second guessing)
So, mutual funds are clearly better in terms of time and money.