Is the KAB Fluid Damper worth it if...

NO, not the ones at $25.19. I meant the ones they market as speaker spike/cones--the first four selections here, where they differ only by color. For example, for black chrome, you'd get this set for $22.88 for a set of four plus shipping.

These include m6-size threads which makes these brass cones a low-cost screw-in replacement for the Technics feet.

Of course, as Tvad said, you then need something to couple them to such as an isolation platform.

I had an extra set of Daytons laying around and gave this a shot, yes they are a direct replacement, however due to the design of the technics they have a swivel boot type footer built into the bottom of the table which is mushy that the old feet screw into and is not exactly easy to get the spikes to stand solid and level.

Also I don't know how effective spikes will really be screwed into a mushy device like this as you are basically still using a decoupled fitting into a solid spike but making it less effective than if the spike was threaded right to the solid part of the plinth. I have not done a comparison, and I have leveled the table via bubble level with the 4 new spikes installed.

I will say from past experience spikes on a turntable have been far better results than any spring loaded, or soft shoe type feet that are normally standard. Higher soundstagging, better more solid bass, and yes even Warmer more balanced dynamics, again not sure how effective screwing these cones into the stock technic footers would be, and it looks like you can not remove or modify the existing footer assembleys, which leaves you with no other options but to go to a Blue tack and stick like a 3 leg cone pattern to the bottom or drill new holes which I do not recommend.

Bottom line go to spikes fitted to the original inserts after removing technics feet and you will have spikes that Sway (or can be bo-legged)and do not stand totally straight due to they will have flexable mounts still.

So are vibrapods under a butcherblock and also above the butcher block with the technics feet left on and resting on the vibropods a good isolation setup?

Radio,
If you wish I do have a full set of the custom made "Vibrapods" but they are actually sorbothane boots made to fit directly on the technics feet perfectly from KAB U.S.A.. they are about 60 bucks a set, They are sitting in a box, I can do like 43 bucks for the set of 4 if you wish to have them.. I would still however probably SPIKE the Butcher block itself to the shelf it sits and then use the Iso feet under the technics feet on the table.. They fit snug over the old ones. Send me an email if interested, I will absorb the paypal fees and ship via Fed ex ground if you want for that price.

Heres a link
http://www.kabusa.com/frameset.htm?/

Kevin of KAB sells three isolating devices: Sonic Domes, Sorbothane Boots, and Isonoe Footers.

He seems to know the Technics tables very well, and I'd put my faith in his selection of tweaks.