Not a Touch owner myself so I am not sure about the current state; but with the original firmware many had problems with stuttering, especially with high resolution files. Most/all of these was removed with some performance improvements in a later firmware, but did it solve it all?!
But I can imagine that if you use the Touch's internal server that you might still be able to get it to stutter once in a while.
Anyway, in the beginning the performance surplus was so fragile that some people even recommnended re-flac'ing to default (5) if one had used high (8). Not sure if that is required today.
About your CPU load; that you see 25% tells us that the program that you are using can't utilise more than one of your four cores. That it uses the one core 100% isn't bad as such.
Jan.
Main: Touch -> Beresford Caiman II -> Carver A-500x -> B&W 704
Office: Duet (Audiocom)
-> Luxman L-210 -> Stax SR84 Pro
-> Beresford Bushmaster -> Superlux HD668B
Server: A8-5500, 4 GB, SSD + 2*1 TB, Win8 w. SBS 7.9 (SQLite w. High Mem)
Tied together by D-Link DIR-655 + DGS-1008D