I just converted my 6' to a 6' stretch. I didn't just halve it, because I wanted to keep my original design of only two parts, each fanfolded together for easy deployment and tape-saving. In the end I decided that ease of transport was more important, so while the walls are still one piece fanfolded, the roof is three. When I fanfolded the roof as one piece, it was too ungainly, with easy-to-damage pointy edges sticking out, so I made it into three sections instead. You can see some of the details here:

errantember.livejournal.com/161605.html

I just did a tack-tape assembly in the living room. There is definitely a stability cost to this design. At Flipside it doesn't matter. At Burning Man, it might. However, with enough tape and tie-downs, I think it would be fine. If I'm still using this hexayurt when I go out to Black Rock next time, I'll definitely bring it. I used the loop-around-the-top method for tie-down, and it survived several bad dust storms.