You have certainly chosen two very reliable replacements for your Rav4, but there are some differences. A 2 year old RDX will be more expensive than a similar Outback, but still under your maximum price point. You can find a 2014 RDX with the technology package, less than 10k miles for around $36,000. The Outback could be $7,000 +/- less expensive. Fuel consumption is about the same - not hybrid numbers but you are turning all four wheels.
With the RDX, you will find many, many more bells and whistles wrapped within a very supple leather interior. The Outback has less features and a rather firm leather seating surface. Navagation in the RDX is interactive and provides real time weather and traffic reporting (for a nominal annual subscription fee, of course). The Outback has a very good nav system and a weather channel on its radio system. It is a bit outdated, but accurate.
You have obviously done some research as you have chosen two vehicles which have the best all wheel drive systems available today. It would be difficult to make a decision if it were based on this feature alone.
Your final choice will come down to creature comforts to your preference. The RDX will have more, but with that comes the possibility of more electronic inventory that could be expensive if replacement became necessary. I owned Acura products for many years, and one Outback. I will say that in all cases, the vehicles went to the dealers for routine service ONLY. I experienced zero, yes zero, failures or warranty-related issues. Both are that kind of quality. Oh, wait - my son got in our Acura Legend one morning and it failed to start. An inspection at the dealer revealed a clogged fuel filter. My bad. Oh, and did I mention the vehicle had 187,000 trouble free miles until this mishap, which in all honesty was owner related. Finally, good luck finding a used Outback with lots of options. Their owners keep them for long periods of time.
Choose your bells and whilstles and make your selection. You will not go wrong with either.