If you're going for a hyper-realistic O scale layout, your MPC engines will stand out like a sore thumb. If you're building a layout that you can enjoy with reliable, smooth-running engines and equipment that pleases your eye (and your wallet), you couldn't have made a better choice.
I love all the MPC equipment I own. I've never purchased any of the notorious clunkers -- i.e., I don't have the Kickapoo switcher and I don't own a Mini-max "boxcar" and I don't own any of the lower-end freight cars with plastic wheels -- but I do own a ton of 9200, 9400, and 9700 box cars and quad hoppers, and tank cars, and, and, and...
...and I'm a happy guy. You should be too.
Steven J. Serenska