If looking for a list of pro and cons to UTA mounting it might look something like this:
Pros:
- Convenience - argo unit is close to the eyepiece so your attention can stay always at the business end.
- Lack of stalk is one less thing to set up (or get broken).
Cons:
- The argo's weight becomes an integrated part of the scope that must be designed in and cannot be separated. Need for higher mounted alt bearings to balance.
- Possible extra wiring complexity if power is otherwise not required at the UTA. Dew control is a good reason to run power there in any case.