sunfire classic vacuum tube preamp

  I have been looking for a tube preamp for some time now.  I would like a pre that has balanced outputs and I am looking for a warmer sound.  I noticed that there are a couple sunfire classic preamps for sale on audiogon and it looks like this could be a good choice for me.  Can anyone with experience in this preamp let me know what the sound is like and if this is a good preamp,  thanks