I mostly agree with audioGM, but I notice that some of FLAC-s with 192kHz sample rate can be demanding and use more than 65% of Raspberry Pi B/B+ CPU. Sometime this can causes audio chopping. From this perspective, more powerful CPU can be useful.
But, most expected upgrade for Raspberry Pi is solution with better/faster LAN Phy, including independent bus, so USB can finally vent

This is maybe task for Raspberry Pi 3 in next years.
Anyway, for same price if we have slightly better CPU, why not
P.S. In my test with HD FLAC I use Raspberry Pi B+ and RaspyPlay4 I2S DAC