Sterling ST 69 tube mic

I'm doubtful if this is the right forum for this topic, but I didn't see one more suitable, so I'll start here and will be brief.
 
I have a Sterling ST 69 tube mic that I've had for a while. I hooked it up the other night and was surprised at how good it sounds of vocals and acoustic guitar.
 
I wanted to see if many of you use this mic, how well do you like it, and what do you use it most for. Seems that I read somewhere a long time ago that it's not for miking an amp cab, so I haven't tried that yet, but wondered if some of you had tried it on cabs and what kind of results you had.
 
Thanks!
DS