Observations:
I have used every putter BUT the old Ghost. I thought the 2010 Redwood was better than the Rossa, and I never tried the old Ghost because it had the same specs as the 2010 Redwood for a lot more credits at a lot later level, so...
I now use the L66 Ghost Spider, and I fully intend to use the L92 Ghost Spider when I get there. The L66 is, for me, BY FAR the best putter I have used. It has every bit the precision AND forgiveness that the 2010 Redwood did with a much slower meter. As a player who plays almost exclusively curves on the greens (as opposed to dings), I can hit my mental mark on the meter consistently. While I am putting about the same from 25'+, from 20' and in I am much, much better with the Ghost Spider.
Unless, that is, it's just a bad day. On those days, I couldn't knock a beach ball into a lake off a dock with an oar.