It's the same offer as on the Amex website. I've had the card for a few years in the past til they upped the fee. The credits make you jump around every month to be able to max them out, so I'd say with the 100k sub I'd get it and only keep for a year, but that's just me. Amex would then hate me for closing it. (pop ups)
Now, if you can spend a lot on groceries 4x isn't bad, but I beat that by using Visa gift cards that I buy with my CIC at 5% while on sale at Staples.
So bottom line is if you want MR's for travel. I prefer earning UR's.