Here is Marriott's conversion table for points to miles. Note that the conversion is much less than 1 to 1.

Here is Marriott's Travel package table which includes a 7-night hotel package plus points. Note that the conversion here is 1 to 1, but the kicker of course is you must also redeem for a hotel stay.

Here is Marriott's webpage listing out a number of non-hotel options. Now as to whether they are good "bang for the buck" really is in the eye of the beholder. In general, since Marriott is in the hotel business and hotel rooms are a sunk cost to them, that is where you will tend to get your best "bang" using points. If you are an elite member with Marriott, they tend to have some elite only rewards that can be nice (i.e. 135K points for $1000 in Marriott cheques).