Yes I have that same problem, but I don't use the Windows volume control to control my volume, I use the volume control knob on my speakers. That doesn't change the Windows volume slider, so it doesn't reset anything.
Another advantage - in this mode, it switches between "Effect" modes instantly. I listen to music in "Stereo x2" and then play games in "6ch Direct". To switch between them you need to go through the Dolby ones, which on the standard one takes about .5 seconds to load per mode which makes it a PITA whereas on the "new" mode it goes over straight away.
Logitech uses cheap, low quality drivers. Fail! I like how everyone goes on about the sound quality being so amazing, but then they only talk about "omg the tang-band 10in subwoofer is so awesome when i turn the bass boost up so high that the amplifier is clipping"
Logitech does use cheap chinese TB drivers only to reduce costs. I think My hsu research based dayton elite sub sound better and gives me control over the crossovers and phase to not make the base muddy and overpowering. And to add my self assembled bookshelf drivers on an old sony ported speaker box with their own crossovers. Also to add the tb 871 drivers used do lack mids but can be compensated by putting it inside a better mdf based enclosure and to get better highs maybe add a good tweeter
EDIT: ill post some links to the drivers used in logitech speakers