I have both, and can link through to Sheraton for 4x Membership Reward points. this seems like the best deal considering I would only see an increase of 1 *point per $ if using the SPG card. Correct forum? it's specific to Sheraton/Starwood and not one card.
The only point I’d make regards foreign travel. With the SPG card, you’ll still get whacked with a foreign exchange fee, which Plat card no longer includes. I’ve now switched which card I use as a result.