ram18
I purchased my current one in 2012. Prior to that I had a C48 for awhile, and prior to that a C15 also. In my opinion, the C15 sounded as good as the C48, so I went back to my current C15. I have had no issues with any of these pre's. I did change out the lights last year, not because I needed to, but I changed the lights on my MC7200 and thought I might as well do the C15 at the same time. It is very easy to change the lights out; all you need is a flat blade screwdriver. I also had purchased led's for the C15 but they didn't fit quite right, so I stayed with the originals.
You can probably stack the amp on top of the C15, but I personally never do that. The C15 doesn't get hot at all, it is slightly warm to the touch. Like I said previously, if you buy it and aren't happy with it, you can sell it easily. In fact, should you want to sell it, contact me first.