I have a classical incision and it's generally studied with the same groups as T and J incisions. You're right, ACOG cites 4%-9% rupture rates with these types of incisions, but the studies that I've found don't have rupture rates anywhere close to that. The studies that I've found generally have a rupture rate of about 1%-2%. It's still high, but the problem is that women that have these types of incisions don't generally VBAC so it's hard to get a good solid statistic and the stats that are out there don't account for different variables like the low-transverse studies do. I have even read the study that ACOG derives their stats from and it's so far skewed and so heavily biased (the author, Dewhurst, was a known opponent of VBAC and opinions show through in his findings). It also happens to be the only study out there that has found classical rupture rates that high. Now, I'm not advocating that everyone out there with a classical, T, or J incision should have a VBAC. It all depends on your personal comfort level. Even though the rupture rates are really about 1%-2%, the ruptures that do occur tend to be catastrophic ruptures rather than just mild dehiscences. For me, personally, VBACC is the way to go. I will be in a very high-tech hospital that is fully capable of attaining a decision to delivery time of under 10 minutes. They achieved this with my first, which was a crash situation and I'm completely confident that they can handle this again. They have round-the-clock, in-house anesthesia and surgeons and one of the most advanced neonatals teams out there. Most of the women on here seem to prefer home-birth, but for me and my situation, this is the way to go and every woman should birth where they feel most comfortable. I feel most comfortable at the hospital that is best equipped to handle a catastrophic rupture. Also, it's going to be very difficult to find a provider. I first tried a group of hospital-based midwives and they turned me away, but they referred me to the OB that oversees their practice. Before I went into my appointment with him, I called every homebirth midwife I could find and none of them would take me on. When I went into my OB consultation, I was surprised to find that he was perfectly ok with my VBACC plans. Up until that point I truly thought that the only way I would be able to have my VBACC would be to birth at home or to go into the hospital in labor and fight for it. It took me just over a month to finally settle with my OB and I was getting very discouraged and depressed up until that point. Just be ready for the long-haul....it might take some time to find someone willing to support you.
Here is some more information on rupture rates:
http://www.emedicine.com/med/topic3746.htm
I also have a wonderful excerpt from the Australia/New Zealand Journal of Obstetrics and Gynecology that deals strictly with these types of incisions. It's in PDF format, though. If you would like a copy of it, pm me your e-mail address and I'll be happy to send it to you! Good luck!
Amanda