While Marriott points are worth more, they are much more difficult to spend. For me, finding availability with consecutive nights at high end properties like Waldorf and Conrads are typically easy with some advanced planning (I like to spend 5 nights a time since the 5th night is free). I have yet to be able to redeem more than a couple free nights at top properties at Marriott brands - calendars are sparse with 4-5 consecutive dates.

I also like the breakfast benefit at Hilton properties and will choose to stay at Hiltons for that reason alone. If you are at a level with Marriott that guarantees breakfast, this benefit is probably a wash for you.

Customer service I've found good and bad at both Marriott and Hilton properties, so that's highly dependent on the individual properties.