Rega RB300 tonearm VTA adjusters


I'm planning to install a VTA adjuster for my Rega RB300.
Which is considered more accurate ? J.A. Michell or isokinetic ?

1. http://www.ebay.com/itm/REGA-VTA-ADJUSTER-FINGER-NUT-BY-J-A-MICHELL-/330315748008?pt=US_Record_Player_Turntable_Parts&hash=item4ce85a52a8

2. http://www.ebay.com/itm/ISOKINETIK-ISOVERT-VTA-ADJUSTER-PLUS-SPEED-NUT-FOR-REGA-/180685503343?pt=UK_AudioTVElectronics_HomeAudioHiFi_Turntables&hash=item2a11b1fb6f
triskadecaphobic
As far as the pictures can tell the isokinetik seems to be the only one made of SS where as the other ones are made of Aluminum.
An advantage, I think...
(The Pete Riggle is made of gold and diamonds :-) )
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Yes Viridian,
I misspelled Triskaidekaphobic which is an album I like.
It means a fear from the number 13.
Man... and I thought my TT has attention to details :-P ...