@sim_audio_nerd I think you are wise in exercising caution here. I've been a customer of Coincident for over a decade now, and still own two pair of Coincident Speakers, the CSL, and the Frankenstein Monoblocks. Obviously, I have a deep appreciation for Israel Blume's design and execution talents. I would also offer an opinion that his stuff is quite reasonably priced. You get a lot for your money.
I think the value proposition probably necessitates some constraints on business practices. I think it is fair to say that he is a superb designer and a hard nosed business man. It's kind of a here it is, take it or leave it approach. Top tier customer service has a cost that someone must pay.
The stereo Frankenstein looks like another superb value, and I suspect it will sell like hotcakes at that price. The reality is that there are going to be some serious compromises associated with this single chassis design. In the past, Israel has explained how important, and how difficult in execution, use of the 6EM7 driver is. Going to the 6SL7 is not just a simple tube switch. My guess is that the performance of this stereo version will be closer to his 300B Dynamo than it is to his Frankenstein monos. Just a guess.
Also relevant here is that in times past, Israel himself conceded that a 300B amp may not be the best choice for the Super Victory, depending upon the things we have already discussed--music, room, listening levels, etc. On the other hand, he has done shows where he has used the Franks to drive the SVIIs, so it's not like one can't make this work. It is just not optimal, and I suspect the stereo version will be another step down from "not optimal."
You don't say in your original post what your current system lacks that you would seek to improve. The obvious inference is introducing some SET magic. I think we all get that, and it is important to note that my system is working so well for me because I am using an SET preamp. You might give some thoughts around that option if you are locked in on using the SVIIIs and if you can live with the limited functionality of the CSL. Just my opinion, but I think the 101D based CSL is Israel Blume's finest piece when used with the superb Psvane WE replica 101D tubes.
I have some other thoughts that are tangential to this post. If you want to discuss further, PM me.