The User-agent string should be an out-of-the-box variable for both Traffic and Conversion (Commerce) use in SiteCatalyst \ DW, Discover or Insight (and be correlate-able or subrelate-able out-of-the-box as well).
Separate from enabling faster deep tracking across platforms, the user-agent string is valuable for those of us who perioidically have to diagnose issues related to site monitoring tools to keep our data accurate. Having the user-agent out-of-the-box (vs. as a custom tag or a VISTA rule) would help us stay more agile when analyzing traffic from new platforms, and also enable us to combat false traffic spikes.
Thanks, CJ