Let's see... I bought my 2013 E+ with... I forget, 200 miles on it? Dealer demo bike. From day 1 it had charging problems, something with the charging circuit itself. Brammo eventually got the right parts swapped out and it's been good ever since.
I'm now sitting around 1,300 miles (I bought it in TX, where I never rode much because the weather is awful, I'm now near Seattle and have more good riding days than TX, or I'd have many more, I assure you!). I didn't ride over winter, and did plug it in a few times to bring the batteries up, and I tend to leave it on for at least a full day after hitting 100% for balancing. Manual indicates that when High and Low pack values are more than 0.1v different then you've got a problem. My H/L diff has always been 0.01, and now sometimes hovers around 0.011. After charging, unplug, and I show 98% available.
My commute starts with a long downhill (but let's be real, regen on an E+ is more about mimicing compression braking than actually getting us power back) at 45 MPH (which is my final leg returning home). Approaching the office I have a 40 MPH uphill that's about, I think, 1.2 miles long) and my initial leg leaving work). Commute is all surface streets, a smidge over 15 miles, speeds vary from 25 to 45. The bike will consume pretty much an ever 22% each direction. While I can theoretically make 2 trips and have 'some' left over, it's really tight and I don't want to push it. Plus, it's still typically in the 40s in the morning, cold enough that regen is disabled for half my ride, so I tend to plug it back in nightly mostly to keep that batteries warm for the next morning. I've only been here a year, and if it rains I don't ride (mostly because people drive like crap) but I do plan on racking up more miles this year, as I'll be in the office more than I was last year. We'll see how the batteries hold as the miles go up.