Thanks for your input Stanley. I love my 5As as well. It doesn't really matter whether the 7 is a little or a lot better in my case because, even after selling the 5As, the difference in price is just too much.
I'll continue to consider the Carbon upgrade even though I really have no place to audition them for several reasons.
1. After seven years of steady use, I like the idea of knowledgable workers taking them down and testing every component to make sure it's working as it should. They build it back up as if it were a brand new 5A Carbon. This of course would also take care of the crossover batteries which are due for a change. According to Richard, this labor is a large part of the cost. It's actually more labor intensive than building a new pair.
2. According to my dealer in Minneapolis, the upgrade renews the warranty as for a new pair of speakers. It also includes dealer setup again which wouldn't hurt to recheck.
3. I trust Richard's judgement and doubt he would offer an upgrade he didn't feel was substantially worthwhile. This is a break even venture for him at best, he was actually losing money on it before he raised the price, so I really doubt he has much motivation to try to exaggerate the improvements to anyone. As Richard put it, plenty of people spend more than the cost of the upgrade on power conditioners, cables and the like for much less, or any, benefit.
I don't know why the model 7 drivers were not used for the tweeter and mid bass drivers as well. I suspect it has to do with cost/benefit ratio but I want to hear Richard's take on this before I make the final decision on whether or not to do this.