Sony TA-F7 vs Nakamichi CA/PA5 mkII


I have a Nakamichi CA/PA5 mkII set, that has served me very well for 15 years. But after reading about Sonys vFet-amplifiers (Nelson Pass is a big fan of these) I have become more and more interested in trying of of these, for example the TA-F7 integrated amp. But there are several problems. First of all I have never heard one, and because they are so rare I don't think I will get a chance unless I buy one. So my first question is: How do they sound, especially the TA-F7, and will they match the Nakamichis? Second question is the reliability. Many of the Sony vFet-amps went bust. Is the TA-F7 better or worse? And if I want to buy one from abroad, how do I make sure, that it works and isn't repaired in a wrong way? All replies is welcome!
olefelsb
Thx a lot for your interesting and informative reply, Sonetduo. As I understand you, the N7/F7 doesn't have the infamous "death diodes", and that's good news. But I'm aware, that a lot of other things can fail. I live in Denmark, so please let me know if you know some people with experience in repairing these amps. And by the way, when we talk about fragility: Would you dare to get one shipped? I ask because I'm looking at one that a little far away for pick up.  

@olefelsb,
If you are interested in an expert that could service these fantastic amplifiers, the closet person to you, whom I am aware of, is located in Holland. If you are interested, send me a PM and I will pass you the contact information.

As far as fragility and transportation, these amps are not especially heavy and if packed well, they would survive long distance shipping.

I have just received one bought in Germany and shipped to Denmark. No problems in shipping. And thank you very much for advice. I will send a PM.