[Barnsnake]

My experience:
1. They are quite responsive.
2. I've been quite satisfied. I had one bad part of their manufacture, an upper control arm that was too stiff at the pivot points. It was replaced immediately. Not coincidentally, that design is no longer used.
3. See #2.
4. If you have been reading the forums you'll know there are as many answers to that question as there are builders. I suppose lack of "detail" in the build manual is the most common "complaint", but with the forums that is no longer a major problem. The combined experiences of the previous builders is more useful than a 5000 page manual.
5. I'm not sure how to answer this one. As I remember (from 12 years ago), after the body and frame just about everything was "optional" in a sense. I ordered what I felt I needed and the finished car met my expectations. Many feel the big brakes are a good idea, especially if you intend to do track days.
6. My 8.8 has been just fine (I'm running drag radials, but not huge horsepower).
7. There are (again) as many answers to that as there are builders. You'll find that there are no two LoneStars alike. That's because the builder has the latitiude to do things "his way". That (to some, anyway) is the beauty of a true "kit" (although I despise that term). It's not like every hole is pre-punched. You can do it the way you like (within the confines of safety, of course).

I've been very satisfied with mine. I really enjoy driving it, but I do miss the build process. In a way, that was just as much fun. Now I struggle to dream up projects to "improve" it. None of them are actually needed.