Well Tempered Classic or Technics SP10Mk2

the well tempered classic is the 'classic' here for sure.

I think it's not as simple as which one is better, because the SP10's that I have heard have been some of the best playback systems I have ever heard, when set up correctly.

The obsidian base and arm should be replaced if you want to compete, or beat your excellent Well Tempered. Some of the great bases for sale on here, when matched with an excellent tonearm (Tri-planar, TransFi Termintator3, SME, Origin, etc) sound absolutely stellar.

But it will take some time and effort. The turntable is where the value is with the SP10, it's rock solid as far as speed stability, so if it's base is stable, and the arm is great it allows you to use many differnt cartridges. I have been thinking about switching to an SP10 too, even though I love my current table. Just seems like fun to match the pieces, and they really do sound stellar.

What is the problem with the Technics EPA-100 tonearm? From what I have read, it is highly rated, can accomodate any type of cartridge due to its dampening method, is made of titanium, very well constructed and is highly sought after?

Thanks for the differing perspectives. I was really hoping that the obsidian base would be adequate for the SP-10. It has been told by others that the EPA-100 tonearm is excellent.
I am not one who wants to engage in a matter of diminishing returns.

IMO, there is no contest here; the SP10 ensemble, obsidian base and all, would cream the WT, if you want accurate unsentimental retrieval of the information on an LP. So there ya go.

And as Dmgrant1 suggested, the EPA100 tonearm is superb and highly sought after. I have serious questions re the WT tonearm(s), on the other hand. The only piece that could be upgraded is the obsidian plinth, but it is not a true liability, either.