Andy, since you asked for it
- here is my opinion.....
I think you are on the right track (that's not a pun!) with a dob. It gives you the biggest bang for your buck (ie aperture rules!) and you do see more - espeically as a noob.
Don't be daunted by the prospects ahead if you want to learn the skies and get around by starhopping. It will take time, but given a star chart and some basic instruction it is quite easy to find things and the hunt and capture can be very satisfying - more satisfying than knowing you managed to push a few buttons in the right order
......sorry got carried away - I know each to their own, what ever gets you through the night, etc, etc,
....climbing off soap box now.
If photography is you niche in life and you want to take some long exposure piccies then you may want to rethink the dob. The 10" dob will show you so much more than the ETX 90 though.
Perhaps get along to a starparty and see how easy a dob is to use prior to your purchase if you have concerns.