As a follow up, in my own experience, fitting, balancing, and using a separate Guide scope (GS) has been quite a challenging experience leading to frustration and plenty of tears when things do not work.
I used to have a dovetail saddle on the mount, then a side-by-side mounting plate with a saddle for my OTA and a saddle for the GS. This set was a bit heavy and cumbersome, but it did up allow me to move the set up side to side (laterally) and slide the OTA and GS in their saddles longitudinally to find the correct balance. I used to change cameras and accessories (Barlows, reducers, etc.) and this affected the set up, so I had to re-balance each time.
The Tak Plate came up on IIS from a member who I had trust in, in terms of looking after their gear and integrity so I purchased it “just in case” and put it aside for a year or so.
I then settled on a camera and system that was reasonably stable and began experimenting and noticed that the Tak Plate would more or less accept my OTA and GS in fixed locations (after drilling a few holes) and the system would be in balance based on my past experience with my gear. This is an important point, as I had gained an awful lot of experience (and frustration) with my gear by having the flexibility to make both lateral and longitudinal adjustments of the mounting plate, OTA and GS in my non-fixed side by side set up. I cannot over emphasise the flexibility that this side-by-side system offered, despite its weight.
The Tak Plate has given me a much more fixed side by side set up. If this had ended up being grossly out of balance, then there would be very limited options to move anything around and I would have had to resort to adding small weights at strategic locations to get balance, which is something I would have wanted to avoid.
So to cut a long story short, my previous experience and tinkering with an GS on a traditional and flexible side-by-side system gave me the confidence that the (fixed) Tak Plate would get me in the right spot in terms of balancing the OTA and GS and that was indeed the case.
I would probably not have started off with such a fixed system from Day 1, as it provides very little room to manoeuvre if your rig does not balance and from hard won experience, balance is critical to obtaining good guiding.
Cheers
Dennis