Once the K-01 arrived, I hit the perfect time to send the K-5 away for a maintenance check. It has the 'dreaded' mirror-flop issue, where a fully charged battery overloads a circuit and causes the shutter to click extra times - it doesn't take extra photos, just sounds like it's doing so. Apparently a cicrcuit-board swap will take care of it, and other inspections will probably detect anything else that needs knowing.
But now it's summertime, and having a rugged camera is more important! I can manage fine with the K-01 as long as the weather is stable, though the screen-only preview is harder in bright sunlight - but it's too bad the timing isn't better. I have the extended K-5 warranty, and perhaps the local Pentax shop can turn it around faster with this summer timing. Anyway that's the next camera expense to plan for, even if it's just postage to and from the shop.