Which has higher priority, overhang or VTA?

Can anyone confirm the old expression for cartridge alignment that if you're off 1/10 degree in any direction of alignment the distortion increases by 100%?

Hopefully you are resetting the VTF with the scale surface at record height, whenever you adjust the VTA on your unipivot arm.  If not, that is what you are most likely hearing.  Raising the arm will decrease the VTF while lowering the arm will increase it.  The change in VTF will affect the SRA which will then affect the overhang.  As Stringreen said, every parameter must be correct.  Repetition and patience will be rewarded.  Choosing between two evils will not.

Isn’t the cartridge/stylus type being adjusted also a prime consideration here?

My personal experience - my standard Denon DL103 seemed to perform very well - setting it up using the free protractors that are available on the web - overhang was close to optimal, but being precise did not seem to impact SQ too much.

VTA did have a marginal effect on bass performance, but I found setting the cartridge such that it was parallel to the surface of a record of standard thickness had little impact when playing 200 gram vinyl

In comparison - my Soundsmith modified version of the Denon DL103 was almost the complete opposite ...
- I initially set it up using the free protractor - then a friend brought over his precision glass protractor.
- Overhang setup was now extremely precise
- Cantilever alignment (as opposed to aligning the cartridge body) was also extremely precise

The improvement using the precision protractor was very noticeable with this particular cartridge.

I still find VTA is less of an issue as long as the cartridge is parallel to the record surface, but ensuring the other settings were precise brought out the very best in this cartridge

I’m still very much a newbie at understanding the "eccentricities" of phono related issues, but I rely on what my ears tell me and for me, using a precision protractor to setup the SS modified DL103 is the only way to go. For the standard DL103 - it was not so demanding

Does the level of precision depend on stylus type ?

The few stylus tyoes I know about are...
- conical (as on my standard DL103)
- elliptical
- Contact Line
- Shibata Style
- Optimized Contour Contact Line (as on my SS modified Denon 103)

Here’s a link that provides many details on this stuff:
http://www.sound-smith.com/articles/stylus-shape-information

Regards...

Some good points above, and my experience has been that VTA has a substantial impact on sound.  Conical styli are unaffected by VTA as they have a uniform cross-section from tip to base.  All other styli shapes are affected to greater or lesser degrees.  You should note that 1 or 2mm of VTA adjustment is quite a large change and shouldn't be necessary very often.  Perhaps you are simply becoming more sensitive to what VTA changes can do?

I respectfully disagree that changing VTA axiomatically changes other set-up parameters, however.  VTA adjustment systems move the entire arm assembly relative to the arm board/plinth and are intended to correct for minor differences in pressing thickness.  Provided that overhang, alignment, azimuth and VTF were correctly set for a uniform reference thickness to begin with, they will remain correct when adjusted to a different thickness.  Changes to those parameters can only occur if the thickness adjustment is incorrect for the pressing being played.  

Those changes are indeed audible, and a big reason why I very much prefer arms that have the ability to adjust VTA on the fly.  I believe your JMW can do that and you can hear when the adjustment is just right if so.  It does take repetition and patience to acquire the skill, but oh, so worth it.

There are a large number of threads here with all kinds of information on this point that you may wish to search for more background.  Many posters disagree with my opinions, many agree and many equivocate toward one datum over another.  One of the more entertaining aspects of the vinyl hobby.  The only real rule is:  Do what sounds good to you.

Good luck & happy listening!

Thank you all for your replies. Sometimes, I just wanted to find a scientific explanation on why I hear better with just a micro adjustment on the VTA. It seems many variables involved. I might just hit a sweet spot on overhang, or vta or vtf. And you are right, in the end, what sounds best to my ear are all that counted. 
THANK YOU