The question currently is: Rent out Cards or Play?
I have tried out both, but I really like to play, so I have gone back to playing. Although it has gotten really difficult, I have noticed that the first days and the last days are the easiest. In between people are going up the ladder, so you'll be confronted by a player in a much higher league. I am normally paying in Gold II, so I always get annoyed when a Diamond player zaps me: "what is he/she doing here?"
So for the season rewards...
6900 DEC... That is currently worth about 100$... not bad! I guess renting out my cards would give me about 2000 Dec/day so I don't know if it was worth it. But I am not complaining :) The other cards are not bad as well. What did you get?
Have you bought/stakes some SPS?
In the next days you will be able to claim vouchers based on your SPS stake and buy Chaos Legion packs! Be sure to get some early as the rewards should be much higher than buying them later :)
The outlook for SPS is pretty bullish so getting some is probably not a bad idea even if you don't plan on gettin any cards.