Are MULLARD NOS EL34s and LTA ZOTL40 REF worth the price of admission?


I'm considering giving an older Linear Tube Audio (LTA) ZOTL40 Ref amp an audition.  LTA has a factory upgrade that includes upgrading to Mullard NOS EL34s for $800 (or less with additional discounts).  I am wondering if quad set of old-stock Mullard EL34s are worth the $800 price of admission?  I don't pretend to know what anyone else's budget is but $800 for quad EL34s seems like a lot.  If I'm paying the premium, it better be across the board and not just improvements on chamber music or obscure Chinese opera (no offense intended).  Does anyone have experience with either NOS Mullard tubes or LTA ZOTL40 Ref amp?  If so, please chime in.  Thanks.
128x128bananaslug

Have you priced out what a matched quad of NOS would cost if you bought them separately?

What kind of warranty on tubes do you get from LTA?

It's your money to spend as you like of course.I have found that I prefer new production power tubes and flavoring the presentation with small signal tubes.I can easily replace the np tubes every couple of years without going bankrupt:-)
@bananaslug,
It is worth it. I love the XF2 Mullard EL34’s and will never part with them. I also have an older ZOTL40 and have taken it in to to get the  latest mods. Check with Mark but I think for the price you will be getting more than just excellent tubes. They now have different/better resistors and Mundorf caps. The improvements from my original ZOTL40, and I do have one of the first ones, is tremendous.
IMO with my ears, no.
I bought new Chinese EL34s from a local tube matcher in Cleveland and they sound wonderfull in my RAM-9mkii.  I would just start with matched new production Chinese EL34's and see how they sound.  About 160 to 200 for the octet.  I can give you the contact info on my guy in Cleveland if you want.