ARC LS26 vs BAT VK-31se preamps

Hands down, leaps and bounds, over the top...ARC LS26. Just buy one and be happy forever. It's really that good...

Yikes!
What an endorsement for ARC!
Being a BAT fan and former owner (VK-300SE) and former ARC owner (LS-1, LS-9, VT-100, VT-100 Mk-III) methinks thy doth endorseth too much!
While I've never heard the LS-26, I have heard the Ref-3 (T.H.E. Show in Las Vegas).
I don't believe the gulf is that wide...
My personal pref is for BAT -incredibly good.

Dweller which bat in the LS26 (6K) price range?

Consider this, the LS26 is NOT an upgraded LS25MK11, no 25 can be converted to a 26, the 26 is much closer to the REF 3 in fact the 26 beats the Ref 2, ask any ARC dealer.
I have the LS26, it would take a very good deal to make me move up to the REF 3

I have owned the BAT VK-31SE, 50SE, and 51SE. I have also had in home auditions of the VK-3iXSE and VK-32SE. Also, I have owned the ARC Ref 3. I would say that the choice would come down to your sonic preferences. The BAT will be more powerful and dynamic, while the ARC will present more articulation and definition. IMHO, The ARC Ref 3 was the best preamp that I've ever heard/ owned.

If your system needs more power/slam, you may prefer the BAT though.

Cheers,
John