I've had great luck at RPR in the past - they key is you have to call in after booking and request the upgrade
My last time there I was only gold and got a King Suite.
At check in, as gold, unless it is slow there is a good chance you wont get an upgrade and it is even rarer to have a suite available for the $50 per night upgrade
I've been platinum and gold at several chains and this is not unusual IMO - there is a big difference in the way Gold and Platinum are treated - and there are a lot of golds
It is great that Loews gets you the upgrade in advance - most other chains dont do that - even for lifetime platinum
As for the special welcome - at RPR it is a fruit plate and a bottle of Fuji water - but they often forget to send it.
I preferred when there was a choice in the past
My last stay there I had to ask about it each morning - finally they just gave me a free breakfast instead great deal as I do enjoy the breakfast in the islands dining room.
Then on the last night they gave me the fruit plate and two half bottles of white wine - really not much point as I was leaving at 6 AM the next morning and I got back to my room after HHN
At SF I was upgraded to a water view in advance and they sent up the fruit plate without issue on the first night.
Be aware that if you book a package it can be more difficult to get the upgrade, I usually have to email the hotel directly.
Not to go off on a tangent, but it is rarely worthwhile to book a package - and getting the upgrade can be a PITA
Anyway - I would not spend the 200 to make gold - I might mention at check in that you only need one night for gold and see if they can give you the upgrade - you might get lucky