Absolutely nothing has gone wrong with this car. Added costs over other cars is based on gas mileage (I have managed 14 to 19 miles per gallon depending on how I drive...) and service intervals (just did the 12,000 mile service which includes changing front and rear differential fluids...).
This is a Jeep. If you have owned a Jeep before (Cherokee or Wrangler are the two I have owned) you understand this. They are harshly suspended, bouncy, can be punishing if driven incorrectly. They are heavy and ponderous. They are Jeeps, there really is nothing like them.
The 2004 Wrangler is aru clutch defect car I bought after owning my Subaru Forester for a year. I had the feeling I should baby the Forester, everything in it was fragile-feeling and insubstancial. In contrast the Jeep is heavily built, functional and tough.
I agree with you assessment. I had a 1996 TJ and had it for 7 years (146,000km) and the only thing that ever let me down was the powdercoating on the wing mirrors. A blast in the city, and the earlier ones had more HP than the current models (Kw quoted in the owners manuals) When I finally found the right tyres for it (Bridgestone), I could actually accelerate in the wet without spinning the back tyres. :)
To lower your running costs you can do some of the servicing yourself. I do my differentials, transfer case and every 2nd oil change myself. There is a great website that covers these procedures with detailed fool-proof, middle-of-the-night-proof, drunk-proof (etc...) instructions:
http://jeep.us41.org/
What I love with the Wrangler, apart from the power, the rugged style and the fun, is how easy it is to do maintenance yourself. Saves you heaps and keeps you busy on the week-end :-P
Cheers and have fun.