I had a Boxercup and the HP2 E at one point, however with a large tail bag and small windscreen I was more comfy on the HP2 E then Boxercup for trips and daily commuting, so the Boxercup just sat even on track days as I was equally as fast or faster on the HP2 E with stock suspension around Barber.
Sold the BoxerCup and then bit the bullet on a 2009 R12ADV that was our demo at the time so extra discount. I never really got attached to that bike, it was just a bike to ride when it was colder out or I needed some hard luggage. I made the mistake of spending a weekend on the 2010 R12ADV that we took in on trade and I was hooked. I now ride that bike more then my HP2 E, but mainly due to cooler weather this time of year and the HP2 E was out of commission pretty much all of last year doing project rebuild to it.
I now have a better HP2 E set-up and it will be my fun commuter, weekend road carver and maybe even track bike.
In short, absolutely the R12ADV and HP2 E can live in harmony. The R12ADV is MUCH more practical and better for the longer trips and doesn't have to go offroad to be a great bike (rarely will mine see any major offroading) and the HP2 E is the hot trophy girlfriend, great for a fun night on the town, not so good to take to family dinners and business outings.