What do you like in an inexpensive tube integrated

By inexpensive I am thinking under 1,500.00 used. Any experience and thoughts on sonics would be welcome.

A Manley Stingray is my first thought, or consider going vintage. At well under your budget you should be readily able to find Fisher, Scott, Eico or Pilot integrated or receivers that have been recapped and brought up to original specs. You might also want to factor into your budget the cost of tube rolling. Good luck!
I've been very pleased with my Audio Space AS-3i integrated. Its price new is about the same as your budget. They are rare on the used market though. Re sonics, there's a review in the back issues of UHF Magazine and I agree with what they say.
Cayin is the way to go, great sound, great value.
Audio Space is manufactured in Hong Kong. Cayin is manufactured in China. Manley Stingray is manufactured in USA. You can call and talk to someone at Manley if you need advice or if you need service. The Stingray sounds much more powerful than its rating. It has a big relaxed sound that you get from high powered amplifiers with delicacy and detail. It's a no brainer.
Rogue Audio Cronus Magnum 90 wpc - USA built, excellent customer service if needed, or simply for asking questions
I second the vote for Rogue Cronus
Sophia Baby Electric,Eastern Electric MiniMax.
I just got a Stingray under your budget and am very happy with it. You don't mention the speakers you'll use it with, which will make a difference. I read that it's best suited for easy to drive speakers, and I agree based on the (only) 2 sets of speakers I tried mine on (my 98db benign 8-ohm-ers, and a friend's 92 db 4-ohm complex crossovers, etc.).
If you do look for a Stingray, go to the Manley webiste and get educated on the various changes from the late 1990s when it was introduced to just before the introduced the Stingray II (now at $5600 or so).
Made in California if that matters to you.
Sebrof, I used my Stingray with several speakers and believe it or not it sounded especially good with my Maggies.
I've owned the Stingray, Cayin, and Cary SLI-80, among others. I've always preferred the Cary by a wide margin. You can sometimes find the Cary for around 1500 used, but they sell extremely quickly.
I haven't heard the Stingray but the reputation of Manley gear is unquestioned. Also the EL84 is a very nice-sounding tube.

I have heard the Rogue Cronus and thought it excellent. It did sound quite different from the tube amps I own, so FWIW do bear in mind that amps don't sound the same just because they use tubes.
listen to Danlib, sli80, we know
Also check out the Conrad Johnson CAV-50. Killer little amp!!
The SLI80 has too many reliability problems.

Thanks to all. The integrated I buy will be used in a second system and will likely use one of the British bookshelf monitors that I have enjoyed in the past, probably with a Magnum Dynalab tuner and some decent CD player, although I may do a CD changer with a DAC just to be lazy.

I am sure I would give it a try in my main system that is, somewhat, ever changing....Audio Research, BAT, CJ, Classe and many others over the years. Speakers have
been 3 sets from Thiel, 4 sets of Maggies and 2 different pair of Martin Logans.

Odd, but I will probably spend more time with the 2nd system.

Thanks to all of you for your thoughts and suggestiohs. Have a good 2012.
Not all at all odd about 2nd system.Many'piles spend more time with 2nd system(my self included} because thats where reality,not our fantasies,tends to reign.
Or, as in my case, you listen more with the second system because it's in a room which is always available, like a bedroom, whereas the main system is in a shared room like the living room.
I've owned 2 SLI- 80 amps in the past 10 years- never had an issue.