Tak FS-78 with Denk standard ( and a question)

Hi guy's.Finally had a chance to use my recently purchased Denk standard refracter package with my Tak 78 and a Orion 120 f.8. Up here in Steamboat the powder has been falling, so my snowboard has been out alot more than my binoviewer, but I've had a couple night's of quick views. I compared my Fujinon 16 x 70 with my FS-78 with the Denks and 32mm plossls (22x?) They totally complimented each other,with the Fuji's being alittle bit sharper on the moon.I was hoping that the Binoviewer would'nt dim the Takahashi to much, but it does. Don't get me wrong; the performance was still awesome on Jupiter and the moon, but my quick peeks at the brighter open clusters show that this setup is going to suffer more than I wanted. I guess that this should be expected with such a small aperture instrument to begin with.The peformance on the Orion is very pleasing.The question I have has probably been asked before, but i'm going to get the appropriate OCS for my 6 and 8 inch reflectors plus a star sweeper for my 8 inch SCT. It seem's that everyone recommend's the 2 inch upgrade over the 1.25. I really don,t understand what benefit that would be with a 1.25 format Binoviewer. Plus I would have to upgrade my 1.25 Everbrite diagonal to a two inch for my SCT. Is it worth it?. Just alittle confused. Thanks