I disabled PCM for FLAC. I only use (AccurateRip)FLAC-files. And I noticed a difference in sound - more in tonal balance with the G98 - now the Touch is decoding instead of the PC. Beside of that imho the soundstage of the Touch is better than that of the G98. And that at a cost of � 215,--!
The Touch
is unreasonably good. However, just disabling PCM stream for FLAC files shouldn't change anything because the default is to stream in FLAC and decode in your SB, so you should have been getting that all along. If the first stream in your list for FLACs is FLAC-native then that's what you'll get regardless of how PCM is set. You can see what you're getting by playing a file and observing what transcoder processes are running on your PC. I think it's best to stream files in original format provided they are native to the SB. My only exception is AAC, where I get mini-dropouts with an AAC stream once every three or four minutes for some reason that I can't fathom, so I transcode on the PC to FLAC - problem sorted. (The next step here is to use VK's work to upsample at the same time).
Having said all this, you noticed a difference and you're happy so that's all that matters.