KT88 Opinions

My Sonic Frontiers Power 2 is due for a re-tubing. Just curious what the consensus is for KT88/6550. So far it seems like SEDs or Gold Lions are the way to go. What are your thoughts?
I'd been using Phillips 6550's in my Cary SLM-100's for a few years and thought they were getting a little weak. The prices of NOS anything(let alone matched quads/octets of anything NOS) nearly left me apoplectic! I tried an octet of EH KT88's(cryo'd), and couldn't get them out of there fast enough(they sold pretty quick on eBay, thankfully). Then I contacted Kevin at Upscale Audio, and he recommended the latest Winged "C" 6550's from the ST Petersburg plant. I was very pleasantly surprised that a newly manufactured tube could perform as well(transparent, dynamic, liquid, extended) as the NOS tubes I'm accustomed to. If you're not familiar with his testing/matching/burn-in procedures, check them out here: (http://www.upscaleaudio.com/product.asp?itemid=16&catid=85) I have no connection to his company, outside of being a very happy customer.
Ducati - Talk to the guys at Doug's Tubes. I went from stock Sovtek 6550s to JJ/Tesla KT88s and more recently to Shuguang solid plate KT88s. Both mftrs. KT88s were better sonically than the Sovteks in several ways. Howevere, the Sovteks were ~5 yrs old or so and I'm guessing not even in the league of your Phillips 6550 to start. I really, really liked the JJ/Teslas but they were not too reliable. Compared to the JJ/Teslas, the Shuguangs seem more detailed, with more hi end extension and air. Downside is a bit of harshness on some CDs(but not vinyl) when listening at louder volumes. Good luck with your decision.
Agree with above..Doug's tubes. The Shuguang Kt-88 solid plate( not plate with holes) is very good as are the JJ's..different, but good.. Both better the Sovtek, EH, and Svetlana tubes. I prefer the SED Winged =C= myself.
I went from Sovteks KT-88, came with my recently purchased Quicksilver V-4, to Genalex Gold Lion. This switch had the same sonic effects as when I replaced the EH 6922 with Amperex 6922 U.S. PQ in my CDP, from thin and airy to full, detailed and dynamic!! I bought matched Quads from the TubeDepot they were great to deal with and fast (no affiliation) so far no problems!!
In my MC275 I just replaced my (still good) SEDs with Genalex Gold Lions and there is no comparison. While the SEDs are Very good, the GLs are vastly superior in detail, bass impact and overall dynamics. I cannot recommend them highly enough.
Genalex Gold Lions are used in my MC275s run in mono. Data sheet says two valves in class AB1 gives a continuous output of up to 100W.

I've used the following to retubed my MC275s and C500T:

[url]http://www.tubeworld.com[url/] is another great source.
I think you're seeing a trend. Genelex Gold Lion KT88 will not disappoint. Used them to replace my Tung Sol reissued 6550--no slouches--and was quite pleased. I have a Cary SLI-80 Signature.
Gold Lion re-issue or Shuguang KT88-98.
I've heard alot of good things about EAT KT88 tubes. No direct experience, but some good words from a respected friend. Good words in the Brit HiFi press. I'd look into them as well.
Check out this thread about KT88


Also a happy camper with the genelex gold lion re-issues, a truly excellent choice.