Golden Tube amps

These look interesting to me and have some good prices. Anyone have some opinions on these? Reliability? Sound quality such as sound staging, detail and of course realism. I have never owned tube, so don't know the problems that come with tubes in general.
Yes, I should have clarified that I've not spent time listening to the SE-40. I did have substantial reliabillity problems with my SE-100 and also read many others reliability complaints about this firms products. It could be that if you got a good one, it lasts a long time, I have no idea.
I had two good ones and they lasted for 4 years with no problems. I thought they had a really nice midrange but the bass was wanting so I sold them.
I have a Golden Tube SE-50 integrated amp. The problem is that I don't know how to set the bias. Does anyone out there know how to do so?

Don't buy them, their sound quality is questionable, I was very dissappointed. Also reliability can easily become an issue & the manufacturer is out of business as mentioned above.
As mentioned, I have a Golden Tube integrated amp and need to know how to set the tube bias. I'm very pleased with the sound of this unit. It has proved reliable so far. I've only had to replace the output tubes, thus the need to set the bias.