I have posted before on the topic of VTA which resulted in me getting into a bit of a spat ie. noone else agrees with me, apart from Rega, perhaps, who provide no such facility on their arms.

This is a summary:

There is a pretty convincing school of thought that says VTA makes bugger all difference. If you have 5 minutes, I highly recommend you read this article, which actually became a bit of a legal issue: http://www.tnt-audio.com/sorgenti/vta_e.html

It explains the relationship (mathematically) between VTA, SRA (which is the important thing, not VTA) and tracking force.

As the reports states in an example, a 1mm change in arm height will change SRA by 0.19 degree. In other words, you have to really make significant changes at the pivot end to make any appreciable difference at the stylus end.

Given that changes in arm height at the pivot end have considerably less influence than any geometric changes at the cartridge end, just think of the relatively enormous changes in SRA that will be created by even the smallest of warps or imperfections in a record, or the difference in thickness between records!

The author's findings made such a mockery of Roy Gregory of HiFi Plus that he threatened legal action...then backed down in the face of the evidence.