I did a little testing. As usual YMMV but here is my two cents worth.
Jade Electrostatic Headphone ( I foolishly loaned my Stax O2Mk2 to a friend and was not able to incorporate them into the listening sessions)
Aragon Palladium Monoblocs (last version)
Stax SRD-7 Mk2 (with speaker switch bypassed)
Wright 2A3 monoblocs
Other support equipment: CARY 306 SACD player, Sonic Euphoria passive preamp, Acoustic Zen balanced cables except with the Wright 2A3 then single ended used.
Musical selections used: Bela Fleck-Flight of the Cosmic Hippo, Tom Waits-Saving All My Love For You, Lyle Lovitt-I've Been to Memphis, Eva Cassidy-Over the Rainbow.
Basically, I ABed everything to compare different setups. I compared the K1K with and without the WEE and the Jades in different configurations as noted below.The results are as follows:
First Place Winner: Jades with the WEE connected to the Palladiums. This gave the best overall presentation with excellent bottom end and midrange, very good soundstaging, and the wonderful detail. The upper range was ever so slightly edgy but I think that was more of a function of my Jades not being completely burned in. I think it would have been perfect with the STAX headphones that I didn't have.
Second Best: Jade with the KGSS. Slightly less detail and perhaps a little congested on complex parts. Actually, this was a great combination but I can help but think that the Aragons gave the edge to the WEE by a reasonable amount. If one doesn't have a fairly good amp/monoblocs then the KGSS is a wonderful headphone amp to have.
Third Place: Jade with the SRD-7/MK2. More congested, less detail. The SRD-7/MK2 is a good starting place for use with the electrostatic headphone as is dictated by one's budget. Once one has a fairly good amplifier the WEE is a no brainer.
Last place: The Jade with the WEE and the Wright 2A3. I only tried this combination to see if the 2A3 (3.5 watts/channel) had enough power to drive the Jades. The volume had to be at about 3:00 for reasonable listening. It wasn't bad but definitely underpowered. What this tells me is that the 300B may work reasonably well with the WEE, or even extremely well and especially with a higher output EL34/KT88 etc amp.
AKG K1000 Headphones:
It was great to be able to use my electrostatic headphones and then with the flick of a switch on the WEE, use my AKG K1Ks by hooking them up to the speaker terminals on the WEE.
I was curious as to if the WEE would impart a sonic signature to the K1Ks so I tried the headphones with the WEE and then direct to monoblocs.
I did not detect any obvious contribution of the WEE to the sound and would be hard pressed to tell if there was a difference.
So, there you have it as far as my initial impressions. The WEE does what Jack intended and does it very well. If you do not care, or your budget does not allow you, to have a dedicated electrostatic amp AND you have a good stereo amplifier or monoblocs I see no reason not to seriously consider the WEE. It delivers!