The t4 editor i downloaded from (sorry forget address), seems not quite stable and not well maintained. it works ok on my office computer (color works but no intellisense), but on my laptop, it is untolerably slow.
T4 editor is an important part of GAT, without a t4 editor, the template authoring task is formidable. I hope MS can provide its own t4 editor in GAT, instead of relying on third party or community personal provider to provide it.
Thanks