I used to cringe at the thought of a slimline and other than the first half a dozen pens that I made, I still have yet to make a straight thin slimline. The nearest I have come is the streamline and the slimline Stylus from TB which I fit with a streamline centreband, so guess that it isnt really a slimline. Reason I don't like turning them I suppose is that I dont like them to write with and as such dont have too much confidence in them to sell them. Additionally people are prepared to pay for a bigger pen in the belief that they are getting more for their money. The thinner it is the more comparisons I find with Bics and the like.
Particularily like the Gun Metal finish on the streamline, its got class in my book! Here's a few I did today

From the left Olivewood Yew Oak, Juniper, Pommelle Sapele Andaman Island Padauk (AKA Andaman Redwood)