Yes the AVID chassis is worth it. Noticed a big difference at our outdoor track in AUS. The buggy felt much stabler over the bumps and held on better around the corners. It just felt all round more planted. I had to change my driving style a little bit in some corners since I had more grip than I used too.
As for the protectors, David from AVID said they still aren't sure what direction they want to take that in and to give them a few days to discuss it and determine what they will be doing.