RE: GO or Carve? From 129 to 170?
It may be simple and boring but it's actually a complex answer required.
For Bft 2, the reality is that even full pro racers on fully tuned maxed out sails on Formula gear won't plane - and the only fun cruising solutions - especially with more practical sails - will be centreboard type boards. (of course we've some rather special solutions in that wind range too, but this doesn't seem to be what you had in mind..)
Bft 3 the FW guys start to get going, but that is still the normal threshold for heavier and less efficient boards such as larger GO's. I don't think many experienced riders would really consider the C133 below 10 kts (which make it almost a Bft4 and above ride, especially if the rider is not super skilled at planing in marginal conditions and/or the wind at that speed is less than rock solid...)
From Bft 4 onwards then the choice is quite easy , as just about any of your options fit the bill and would work well : choice would come down to other factors such as (intended) ride style (moves vs crooze), budget, durability (which is often a real issue with advancing riders) vs weight (which relates to durability but also early planing performance etc) , resale (if you decide to take an intermediate board now with a view to having a more suitable board short term and then upgrade to a more advanced one later - this is actually a pretty good attribute of the GO, great resale) and so on..
So I'm not sure if this is the news or answer you really wanted to see.
But hopefully it gives you a little more to consdier, and if you'd like more info or discussion, please let us know. The best guy is Roger, it's totally his thing ~ and he's a wealth of practical knowledge and experience of the boards in these conditions.
(the rest of you will all have a laugh about me writing about Bft2
... but let me tell you that Serenity is fun - even in BftONE!) B)
Cheers ~ Ian