Russ - Many people advocate that strategy, however, you can get both the traditional perceived "tube sound", high power, and/or a highly detailed sound from different tube equipment manufacturers. Just ensure that the equipment is compatible with each other (e.g., direct-coupled or not) if you mix manufacturers.
Also, some solidstate equipment is not as edgy/over- detailed/electronic-sounding as anti-SS people would have you believe.
You're doing your homework which is great! You can look up my system and see which way I went, but I'd be the first to admit that it was an evolution and didn't happen all at once. If I made a change in my system I'd probably go for additional tube equipment but I'm fortunate in that my SS integrated amp (Plinius 9200) has much of the sonic organic quality that good tube equipment has.
Terry