Hey there,
I build PC DAWs and it's true that the VIA chipset is/somewhat was >a< cause of the audio dropouts, clicks, pops etc. when recording several channels of audio at once but, not all soundcards have these problems. The M-Audio stuff seems to work fine as well as Echo. RME and other companies firmly advise against VIA based boards but in my experience, I've found that the AMD 76x chipset boards like the Epox 8K7A works great with most cards. They have the VIA 686b Southbridge but I haven't encountered any major glitches. Try to avoid USB midi interfaces. During tracking and playback, I've found that active USB devices often cause the dropouts and glitches.
I personally have an M-audio Delta 44 along with an SB Live for midi interface on an Epox 8KHA+ board (VIA KT266a) and haven't experienced any serious glitches. I have all the latest drivers and BIOS running Win XP Pro. I do almost everything in Sonar 1.3.1 and I frequently record all 4 channels at once through the Delta.
The nForce boards work great for audio but there are occassional cards (ie: Motu PCI 324) that don't behave with AGP video installed that is remedied by using a PCI video card. The n415 is the chipset in question. Not sure about the 420 but the nForce indeed does smoke. Tested on an MSI board.
Generally speaking, VIA chipsets can work for you as long as you install everything carefully. Install the OS, then install the latest 4 in 1's then the rest. Try to install in Standard PC mode if you have problems with having all your devices on 1 IRQ. Sometimes you might have an IRQ being shared and that might be the cause of the audio glitches. ACPI mode can wreak havok on your system for audio but sometimes can work beautifully. If you want perfect audio performance, go with Intel. You wouldn't believe how much of a difference there is with realtime PCI DSP cards. (something like 16+ realtime reverbs on Intel versus 3 at most on the Via boards. AMD 761 handled about 6+ but choked on the first one.)
Most consumer cards won't have any problems with Via so most of you can't confirm this but in the DAW application, the problems are real but most of the time, it's user error. USB blows chunks for audio though. Try printing something while playing back audio on any card to a USB printer and you'll see the problem, accentuated.