After a lot of research I bought an Esprit 100ED 12 months ago as my introduction to astrophotography. It was easy to use as a beginner (particularly as it came with a field flattener and everything needed to connect to a Canon DSLR). I've learned a lot since then and don't feel like a beginner anymore but it still doesn't disappoint and I'm sure it won't disappoint 5 years from now. I upgraded from from a Canon DSLR to an ASI1600mm. I do get halos (particularly with narrowband) but that's down to the camera/filters, not the OTA (
this as an example). I can strongly recommend an Esprit.
Kevin