I purchased the spider ghost (L66) when it first hit the shelves and gave it a lenghty test. I had initially hoped it would replace me Daytona Rossa (L55) which I had grown fond of (at the time my putter of choice). The extra dot and a half I felt was a no brainer.
Having used the putter on all courses and attempted all sorts of difficult putts I decided to shelve if after (2/3 weeks of testing) . The sole reason is that on longer to mid range putts where power ( 20/30/40/50) is required the spiders attempt can fall anywhere up to 7/10/12 feet short if the ding is missed (even if missed by only a fraction). It is those long putts that you need help from your putter and the L66 Spider Ghost does not provide that. On the contrary, it now gives me the sh*ts.
I reverted back to another putter the Daytona Ghost (L84) as that came with more precision but crucially when faced with a long putt, I knew at the back of my mind that if I missed the ding the putt would still travel the set amount (if not then very, very close).
I must thank the Spider Ghost (L66) as it showed me how good my Daytona Ghost (L84) was. Up until then I had been a Daytona Rossa (L55) man through and through and had not fully appreciated how good my Daytona Ghost was.
The Daytona Ghost (L84) is now my putter of choice hands down. I recently made an 88 footer with it having missed the ding. I know hand on heart had I attempted the same putt with the Spider Ghost (L66) it would have fallen 15 foot short if the ding had been similarly missed.
So New Ghost vs Old Ghost. Easy for me, Old Ghost !
Hope this post helps