After much deliberation I have replaced use of the TextRenderer and gone back to the GDI+ text drawing. It is a simple of case of deciding which has the worst side effects.
On the plus side for the TextRenderer was the more accurate measuring and drawing of text so that controls would be sized very accurately. On the negative side we have the inability to draw text with anti aliasing in the vertical orientation. To begin with I thought this was only going to be a minor annoyance and so worth the price but on reflection that is not the case.
Instead I have rewritten the text drawing, for the third time, to use standard GDI+ drawing. So now we have the use of gradient colors and images for the text and a consistent appearance in all orientations. Dealing with the inaccurate sizing is a pain but within bearable limits.
It is frustrating spending so much time going over the same ground until you reach the right decision but at least I know I have explored all the options!
