I don't know what Captiva you tested, but its nothing like mine.
I have a 2016 Jan build LTZ. Noisy diesel engine? It's noisy on start up but it's quieter than I thought it would be on idl. Inside I cannot hear it, wind the windows down and it purrs. Economy? I am getting 8.9l 100kms. It has more than enough power.
Comfort? I drove from Brisbane to Rockhampton, didn't get a numb bum as I do in my Falcon. It is bigger than I thought it would be and it has plenty of room inside. I can adjust the electric drivers seat to suit me. The reversing camera and front and rear sensors are great, I thought it was a bit gimmicky but using them, wouldn't be without them! I like the heated seats good for my arthritis and back. Its easy to get in and out off for an old person!!
Free servicing for 3 years is great. I do get rattles in the dash but thats on certain road surfaces, not the car's fault.
It is great value for money, $10k cheaper than a Hyundai Tucson Highlander or Kia Sportage Platinum. Ford Kuga is way over priced and at $50k you have to pay $1300 for Tech Pack! I believe Kuga Titanium should have Tech Pack as standard.
It is built to a price and does what is intended, It's no BMW X2.
What I would like to see in future models?
Folding mirrors and a bigger fuel tank.
I researched other similar cars and the reviews are not much better than the Captiva. What were you expecting? Audi, BMW quality!