Best DAC from $1500 to $2500 or so


I currently have an eastern electric minimax dac with a mullard tube as well has a musical fidelity v-link asynchronous usb->spdif feeding it. From what I've read the EE seems like a giant killer (especially with the MF v-link feeding it). My question is, how much would I have to spend to actually make a significant upgrade to this DAC. Would dacs in the $1500-$2500 range really sound that much better? Has anyone compared the EE to some in this range:
Ayre QB-9
Bel Canto 2.5
blue circle 507
Neko D100
Wyred4sound Dac-2 (6moons says this one isn't much better than the EE)
red wine audio isabella
wavelength brick
ps audio perfect wave
audio GD- NFB-7
weiss dac-2
Audio note (whatever dac of theirs is in the pricerange)
tranquility DAC
linaeum66
Linaeum66...I just want to make sure you have seen this article/review about changing the Opamps in the EE Minimax DAC by Doug Schroeder in Dagogo.com. It seems like it has made a huge difference in upgrading the sound quality for a minimal investment. Also Doug Schroeder is a member on Agon and I am sure can walk you through this further. Here is a link to his article on this: http://www.dagogo.com/View-Article.asp?hArticle=864
I think with a tube and op amp mods, there is not much that will beat the minimax. The reviews seem to suggest weiss et all will give a more refined but less organic presentation.
I went from an EE mm to a W4S Dac-2. It was not an improvement to my ears, very similar. The Dac-2 though had balanced outs and asynchronous USB options which I wanted. Unless you need more flexibility, the EE for sound quality is hard to beat IMO.