I'm getting very mixed results after using KTC in my ECO for a day.
First off, with the stock 1.1mm ECO stub the pen would only write with unreasonable pressure applied. Otherwise the ink would not travel to the end of the nib.
I got better results when I swapped in a FPR 5.5 medium nib. It writes very wet and shows off the ink well, but occasionally the ink won't make it down the nib again and I'll have to flick the pen slightly to resume flow. I think the ECO feed, at least on my pen, just has a really hard time maintaining ink flow with KTC. I was a little surprised by this because I know that the stub version of the ECO has a wetter feed than with the other nibs.
Has anyone else experienced this flow issue?