I agree, the 740 is a much more reliable choice. Notable wear items on our 740 wagon (210 K miles and counting) include the front thrust rod bushings, A/C compressor, water pump, and radiator. Plus all the plastic bits in the interior tend to disinegrate in the hot sun. The wagon will hold an amazing amount of stuff. Change the oil and timing belt at the recommended intervals and the car will run forever. Put Bilsteins and and sway bars on if you want a firmer road feel. I heard that the sunroofs in the wagons can leak. If you can find a wagon without a sunroof, that's a plus.
Good Luck.