Just because it was stated my the chip manufacturer does NOT mean that it's right!

I work with high end telecomms equipment, upto 10GB/s and we have had several issues with noise and equipment failures, all of which can be traced back to the manufacturers recomendations. We have even had them admit that they chose a particular layout just because a competitor did.

One case involved a 200MHz processor from a very well known company, that would not work reliably on some units if the temperature was low (we need to work @ -5C, they were failing @ +20C!). The cause - Layout and decoupling on PLL supply pins.

As for solid power planes, yes they are good, if the layup of the board stack is correct, as they then play a part in supply decoupling.