How important is Impedance matching between solid state preamp and tube power amp

I've been away from these forums for quite awhile and, in the interim, have made some changes which seem to be working well for me. Two local guys, though, expressed concerns regarding impedance issues and how I would be better off all solid state, all tubes or, if I insisted on mixing the technologies, put the tubes in front. I understand the validity/logic for each of these combinations as well as what I have chosen in the current setup. In regard to impedance matching it's something that I've paid little attention to in the past thinking it was not an important enough issue but, in reading articles on the matter, several experts seem to have strong opinions regarding impedance ratios.  What I'm asking is, who's right?

Here's where I am now. Not based on an overall plan, I've gradually reverted, piece by piece, to a bunch of older components, even abandoning my 30 plus year devotion to Martin Logan speakers which freed up a some latitude in power amp choices, especially regarding amperage considerations. For general everyday listening we're using lossless music files through first generation Applle TV which I have been quite happy with. For single CD listening I'm now using the very old Theta Data Basic transport and Theta dsPro DAC. For multiple CD play we have the Sony cx777es with the Escient manager. Everything except Apple TV currently routes through the Theta DAC. Ok, here's where the question arises; everything routes through the Peachtree Nova hybrid integrated amp, used as a preamp, to the Cary Rocket 88R amp and, finally, to the Serie Reference 3R speakers.  Like I said, old. 

I know that there are newer components that, from a technical standpoint, do a superior job but this combination of components sounds as good or better to me as anything I've ever had in the house and I know that should be reason enough to accept what I have and leave well enough alone.  Anyway, most of us, seemingly, no matter how far we come toward putting together the perfect system, are open to advice from those who are more knowledgeable.  Any comments would be welcomed and appreciated.