I do not have any high-end refractors (AP, Tec, Tak) but I have looked through AP and especially Tec-140 and Tec 160 a number of times. And, I have compared the Tec and APs to my own ES127ED and SV125 enough times to draw some personal conclusions. I have compared on a couple of occasions the TEC 140 with the ES and SV directly (side by side).
Visual Impressions only (no AstroPhoto and not a formal comparison) :
1) CA: The color differences are small. I have seen CA in every refractor I have looked through. Granted, I tested on some tough objects (Venus, Sirus etc). The Tec and APs have better color control, but it was not by much.
2) Sharpness: The Tec and AP were sharper. Stars were tighter. It is not by much, very little, but the differences were present.
3) Contrast: This was the biggest difference and very noticeable. The background sky was blacker and the stars (star-fields or star clusters) brighter and just seem to pop-out more.
Another thing that one has to keep in mind: Quality control is greater with high-end and there will be more variation with mass produced.
You get what you pay for and that is the way it should be.
If one has a good, mass produced scope and does not enjoy the view, well I do not know what to say.
I appreciate the mass produced scopes I have but if I could afford a TEC-140 and a rock solid mount and tripod to go with it I would get one.
P.S. I find the ES and SV are optically indistinguishable.
Edited by BoldAxis1967, 12 October 2020 - 11:50 AM.