Marriott points will transfer to airlines at 3:1. UR points transfer to a smaller set of airlines at 1:1, and also have the option to transfer to Marriott at 1:1.

So for an equal number of UR or Marriott points, the UR points can do literally anything the Marriott points could, since you can transfer UR->Marriott and do whatever you want in the Marriott program, including transferring the points on to various airlines at 3:1 if you really wanted. But the UR points can also do things the Marriott points can’t do, like transfer 1:1 to United (thus offering a better return than Marriott points) or transferring 1:1 to Hyatt (thus offering something Marriott points can’t do at all).

So (setting aside the travel packages), 60k Marriott points could become 25k BA miles for example, but 60k UR points could become 60k BA miles.

So if you had both cards and were choosing between using a card that gave you 3 UR points per dollar on dining (the CSR) or 3 Marriott points per dollar on dining (the SPG Luxury Amex) you’d always choose the CSR.

That logic obviously doesn’t work if you don’t hold both cards, though — but a lot of people do already hold the CSR (and IMO anyone who spends decent amounts on travel and dining probably should have it, arguably as a higher priority than the SPG Luxury Amex).

That logic also gets more complicated if it’s not the same number of UR or Marriott points —for example on non-bonus categories the new Marriott cards will offer 2 Marriott points per dollar while the most UR points you can get in non-bonus categories is 1.5 per dollar on the Chase Freedom Unlimited. If you really really wanted Marriott points you might choose the 2 Marriott points over 1.5 UR points, though for most people if you investigate the value of UR’s other use options beyond transferring to Marriott, I think you would come to the conclusion that 1.5 UR points is worth more than 2 Marriott points.