I've been thinking a little more about this — and each system has different advantages and limitations — and the user has to look at all of those and weigh them against each other to come up with
the best scope cam system FOR HIM/HER! Following advice like "buy X" or "Y is trash" isn't all that helpful, unless it comes with specific reasons why X is "better" than Y for the poster that makes the recommendation. It might just turn out that what is a huge advantage to YOU is negligable to the OP.....
Here're are a few more factors to consider:
(1) The field of view (FoV) of many electronic scopes is narrower than one would expect from the stated bottom magnification. If you do
rushed close range shooting or have rapid moving targets, this might be something worth considering.
(2) The add-on scope cams can be mounted on
any scope, of with which you are
already familiar, with
any magnification range you prefer, with the
reticle you already know because it's your scope.
(3) Add-on scope cams cannot be mounted on certain scopes, or with difficulties only.
• Scopes that have a
IR pimple on the eye piece: The camera-to-scope adapter will not have much space to hold firmly onto the scope (and [for some models] support the weight of the camera).
•
Compact scopes — because the eye piece is so close to the turrets this might limit the ways you can mount the camera adapter.
• Scopes with a
very small or very large eyepiece.
(4) Add-on scope cams usually
increase the "length" of the scope by a couple of inches — because of the "extended eypiece" through the scopecam adapter.
In order to keep your eye/cheek placement you'll have to move the scope forward by the same distance that the eyepiece "got longer" through the adapter.
For some guns (magazine sticking up, or a short rail on a pistol) this might be tricky.
(5) It seems that some add-on scopecams
need a scope with a "normal" eye relief (say 3.5" to 4"). There are scopes* out there that have an extremely short eye relief — but they are extremly few.
*Prismatic scopes; and: MTC Viper Connect; Hawke Airmax
30 Touch 3-12x32

I have been very happy with my 1-month old Tactacam.
Matthias