I didn't have any issues with the wheels going out of true, in spite of the fact that I lent them to Liam Glen to crash in the mountains. That episode did manage to put a bit of play into the front bearings, though. If you loosen off the axle with a 5mm allen key in each end, you can tweak the cone position by hand which is a simple enough job.
Overall the WH-6800s put in a good performance. They're not the lightest you can buy for the money but they're well built and stiff, and good for anything up to a race. At the recommended retail price of £329 they'd be a very decent upgrade to the stock wheels on a mid-level road bike. If you shop around you can get them for a fair bit less than that though, which makes them a good buy