Wrt trips out of Rio I would echo avoiding the Amazon as it's too far. I would go to Iguacu Falls which can be done in 2 days and is definitely worth seeing.

The Marriott is fine albeit a little sterile. I preferred the atrium view to the ocean view as the windows and rooms are quite small. I don't think it's worth US$220 never mind the regular rates but I would agree with the others that compared to what else you'll get for the money in Rio it's a good deal. Plus it's guest friendly.

I wouldn't get too hung up on the Ipanema is better than Copa issue. I tend to go out more in Leblon than Ipanema but both are less than a US$10 cab ride away. Also safety and nightlife in Copa has improved in recent years e.g. 10 years ago where Domingos Ferreira meets Bolivar was pretty dodgy. Now there are chain bars such as Belmonte and Devassa there that are busy most nights of the week. Also bars such as Mud Bug where you can have a wider variety of beers and check out the local scenery. Having said that I'm often just as happy a busy neighbourhood botequim with a nice cold bottle of Skol in front of me.