John, like you I also have a NP-101 and a Tele Vue Bino Vue. I got a Denkmeier OCS last month and have been able to use it a few times. It definately works well with the TV Bino Vue. With a pair of 24mm Panoptics I'm now able to binoview at 29x. That gives me a field that is 55% wider and a field area that is 137% larger than what I can get using that same eyepiece with Tele Vue's 2.0x corrector.
This extra large field (especially for a binoviewer) comes in handy for both locating objects and for observing rich star field areas like the summer Milky Way or Saggitarius. It is also great for the larger Messier objects like M7, M24, M31, M44 & M45. However, many of the other M objects that look good in a binoviewer (e.g., M8, M35, M42, the Double Cluster, Alberio, etc.) will look better at 45x using the regular TV Bino Vue than they will at 29x using the Denkmeier OCS. Which one will work best depends on what object you plan to use it with.
I also reconfigured the Denkmeier OCS to see if it would work at a higher magnification and it did. I not sure of what the increase was but I'd estimate that it was somewhere between 3.0 and 3.5x. However, I don't plan to use that option very much because my Tele Vue Bino Vue (at 2.0x) gives me more than enough high power options (using the 9mm or 7mm Type 6 Naglers) that I don't need the Denkmeier OCS to provide that option for. However, depending upon which eyepieces you currently own that Denkmeier high power option might come in handy.
Is the Denkmeier OCS easy to use? I'd have to answer both yes and no. Once you get it setup it works just as easy at the Tele Vue 2.0x corrector provided that you remain in binoview observing mode. However, if you want to switch back to single eyepiece mode to view and object then you must
1) Remove the diagonal from the OTA. (2) Unscrew the Denkmeier OCS from the front side of the diagonal. (3) Reattach the diagonal to the OTA. (4) Put you single eyepiece in the diagonal and then start observing. Then, in order to go back binoview mode you must reverse the process. In this respect I don't find the Denkmeier OCS easy to use. With the Tele Vue 2.0x corrector switching between single eyepiece and binoview modes is as easy as switching from one eyepiece to another to change the magnification.
Another thing to keep in mind that that you will need to switch back and forth (between modes) quite often. While many deep sky objects look great in a binoviewer, in my opinion the majority don't look as good due to the light loss. Hence, I tend to do about 75% of my telescope observing in single eyepiece mode and 25% in binoview mode.
Nevertheless, the Denkmeier OCS can do some things for you that the Tele Vue Bino Vue alone cannot. For that reason I
can recommend it to you. I'm glad I got one and look forward to using it a lot more next summer.