Need knowledgeable feedback on a telescope...

Like the others have said, Conan, it would be limited it what it can show visually. But it's certainly better than no telescope. Its its about equal to the telescopes that Messier had, at least regarding light-gathering power. To be sure there's enough things to see with a 90mm aperture to last a lifetime. But with its 3-1/2 inch aperture, there's a lot of sights that would be out of reach. Resolution of any globular clusters into stars (rather than a fuzzy ball) would be marginal at best. Not only would resolution be limited but light-gathering power is quite small. The Moon, Saturn and Jupiter would be nicely shown, since they are bright. But many galaxies would be very dim. If this model is a Go-to scope with say a 40,000 object database, the majority of these would be barely visible if at all.

Regarding astrophotography, you could do snapshots of the Moon, since it is quite bright. Hanging a camera off the eyepiece end would present problems with balance. Only if you could tip its alt-az mount up on a wedge (turning it into an equatorial) could it be used for long exposure astrophotography. Bear in mind that it has 1250mm focal length at f/13.9, which limits its use to bright objects. While you could photograph faint objects with longer exposures, then tracking and polar alignment become more of an issue.

I did run into this link which indicates that you can attach Schmidt-Cassegrain focal reducers to the ETX using an adapter. It has some warnings about weight issues with hanging a heavy DSLR off the plastic ETX rear cell. With the Meade f/6.3 focal reducer the ETX becomes 790mm f/8.7 - with the f/3.3 reducer it becomes 415mm f/4.6. These would certainly give a wider field and shorter exposure times.

https://www.astronomics.com/meade-etx-sct-thread-back-cell-adapter_p11924.aspx

But overall, I would not highly recommend an ETX for astrophotography. But I'm sure that some others have had a measure of success using one. For visual use it would have some utility. All of this is just my opinion.

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Best Regards,
Russ