Overall, I find this car to be a pleasant surprise. After growing tired of my 1996 Acura Tl (which by the way was a very reliable car), I was in the market for a small multipurpose vehicle.
The BMW X3 caught my eye because of its practical nature and the prestige associated with the BMW brand for a reasonable price.
I ended up purchasing a 2005 Flamenco Red X3 2.5i with the beige leatherette interior and the following options:
Steptronic automatic transmission, panorama roof, cruise control with multifunction steering wheel, on-board computer, and BMW assist. The total price was in the range of 34000, thanks to a clearance deal.
My first impressions of the car are generally favorable. I am very impressed with the steering and road feel of the X3, in fact it handles much more like a sports sedan than any SUV I'm familiar with. I will have to wait until winter to comment on the benefits of the all-wheel drive system, but so far so good.
As for engine performance, the standard 2.5l six produces 184 horsepower and 175 lb-ft of torque. Though fine in the 325i, the engine becomes somewhat overburdened in the X3 due to the extra weight. BMW's website clocked the X3 2.5i with automatics 0-60 time in 9.3 seconds. To put that in perspective, a Honda CR-V, an SUV with many of the same features costing around 15000 dollars less, clocked an 8.9 second time with a 4 cylinder engine. Moving up to the 3.0l six offered in the X3 can bring prices into the 40000 range, at which point you may want to consider an X5.
I personally don't find the engine to be a major problem because it is something I can simply adjust to. Besides, you still get that signature BMW feel, just with less thrust (which is all the better for you, because you'll be having fun while getting fewer speeding tickets). The only time the engine becomes a noticeable problem for me is during around town driving on hilly roads when there's five cars behind me, at which point I'll have to bring the tachometer into the 4000 rpm range to offset the lack of torque. Ultimately, most people in the target audience of the car probably won't even care.
I thus recommend this car to anyone in the market for a small SUV with a car-like ride and the prestige associated with a brand like BMW. If the prestige factor isn't a necessity, you might find better value for your dollar in a Honda CR-V or Ford Escape.