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
Regarding the 1 1/8 hole needed...
This is the tool for the job, right ?
http://www.ebay.com/itm/Irwin-10239-Unibit-9-High-Speed-Steel-Step-Drill-Bit-7-8-and-1-1-8-/300791331175?pt=LH_DefaultDomain_0&hash=item46088f7967
Post removed 
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 :-) )
Post removed 
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 ...
Post removed 
I have an origin live vta adjuster which I find a major PIA to use. You have about a whole mm of surface area to grab onto which is basically flush with the top of the armboard. I don't have particularly stubby fingers so I could only imagine how much worse it could be to use. I wish I had the speed nut or riggle product if it was applicable.
The Riggle is easy to use. An alternative if you want something easy to use and a Rega mount is an Audiomods arm for about $1,000 new. I picked the Riggle.
I got the isokinetik VTA adjuster for the Rega RB300 tonearm and found out that the thread did not fit the RB300. While the original nut fits the the thread of the RB300 beautifully the VTA adjuster doesn't.
Thinking it's a matter of bad thread I sent it back to the dealer and we agreed that he will ship me the "Michell" one instaed.
guess what ? ...The "Michell" didn't fit either !
Is it a case of both having bad threads or does my 1990 Planar 3 have a different thread than the one nowadays VTA adjusters are designed for ?
Interesting. I think you should call Pete Riggle. He is a nice guy and might be able to help you.
I called Michell Eng and they agreed that I'll send them back the VTA adjuster together with my original nut. They'll speachialy produce a VTA adjuster that will replicate the thread of the nut that I have.