I have owned and loved the '09 RDX for a year now. All around it is a great package. The engine is a strong point because it offers wicked amounts of power when and where you want it. It eats more gas if you are heavy on the throttle, which most are because it is amusing. Everyone cried about gas mileage with the 12.5/100k in the city numbers. I get that if I don't abuse the throttle without any problems.
Have a look at all the city numbers for all the vehicles that you have mentioned, such as V6 Rav 4 (with it's lovely economy car interior, and clearly not a driving enthusiast's first choice), Tiguan (far less power performance and cheaper looking, Golf themed interior), Mazda CX-7 (I drove it too- cheap interior, rough ride, low quality feel-totally justifies its much lower price). The cost significance in the difference of fuel consumption over 100km is like $1-$2 for the 100km. After driving all of these vehicles and others, the Acura is where most would want to spend their money.
The RDX weighs almost 4,000lb, so the TSX V6 that everyone keeps thinking would get better mileage in the RDX than a turbo 4 is totally lost. It won't happen. They would likely be so similar that the swap would be a waste. Also, the 260tq that the turbo puts out at low revs compared to a larger displacement V6 that would have to rev way higher to achieve is a silly argument.
I raced a Rav 4 V6, all it saw was RDX tail lights, as did an RSX-Type S, which is what I drove before getting the RDX.
The only real competition for the RDX is the Infinity EX, Merc GLK, BMW X3, or Audi Q5. Go check the numbers, all of which are very similar for fuel economy, regardless of the optional engines (excluding diesels-and their lack of performance). Each of these vehicles offers something unique the others don't. Some are nicer than RDX (like the GLK and Q5), but don't kid yourselves, none are cheaper, however the EX is dead even for cost. The X3 doesn't even come with leather seats while starting at a price similar to the RDX, and the Merc gets way costlier than the RDX real fast.
Anyway, the fuel economy in this thing could be better, but this vehicle is meant for people who like to actually 'drive'. You want to save $1 on gas over a 100k in a Rav 4, go right ahead, the additional savings in sticker price of your choice is because it is not remotely in the same class as the RDX....for anything. Same goes for the CR-V.
By the way, everyone who rides in my RDX loves it, women and men alike, as well as my friends who still drive small hot hatches or Subaru WRXs. AND the SH-AWD in this thing with the winter knobbies on makes the snow covered roads/highways of Halifax feel like a summer day.
