WO Zenithstar 73 or other?

[mos]

Hi folks,

I'm looking to buy a refractor intended only for astrophotograpy and so far the Z73 @ f/5.9 (https://www.firstlightoptics.com/william-optics/william-optics-zenithstar-73-apo.html) is standing out as a good option around an ideal lower budget. I also like that it has a matched flattener with adjustable back focus that doesn't reduce the field further. I am a fan of wide-field views, but with my 1600MM I would rather stay under 2"/pixel as my seeing down here can be very good. 

I know it is a doublet but from what I have read, CA could be very well corrected at this aperture and speed? 

I haven't been able to find many posts of people's experience with it and was curious if anyone has one and how they find it? A solid focuser is a huge plus for me. 

The other option is to go for a triplet. The GT71 looks great as do others often recommended, but with what I think is a looming purchase of a Pixinsight licence I would like to save where I can.  But if spending more on a triplet over a doublet really is a much better option for imaging then I'll find a way ?

 

Any advice and insights appreciated as always.

Matt