OK, first the disclaimer. It's your bike, ride it however you want, as long as you don't crash into me.
Having said that, so far there is nothing but misinformation and misunderstandings in this thread. All of the data and marketing materials supplied by BMW talk about the advantages of the Integral brakes in terms of full-on panic stops. Even the load-sensing circuits and memory only engage after ABS is activated on one or both wheels. That makes sense, as there's no "weight sensor" on the bike to detect differences in actual load, or traction for that matter. They do talk about "reduced lever effort" and "increased braking force" which is available at all speeds, but that's just the power boost making it a bit easier to stop and has nothing to do with which lever is acting on which wheel.
The Integral brakes are not
like the older linked brakes you may be familiar with from previous Hondas which were purely accomplished with plumbing tricks. The Integral ABS unit uses a sophisticated set of control circuits to sense the input from the front and
rear levers, and adjust the braking force based on the proportional inputs. Note the word proportional, as it does sense the inputs on both
levers at all times, and adjust actual brake application accordingly.
And the difference between Partially Integral brakes and Fully-Integral brakes is only
that the Partial version does not have feedback from the rear lever to the front calipers. All else works just the same.
Now let me state this clearly: the front and rear brake levers are not
identical or interchangeable. Using the front only is not
equal to using the rear only is not
equal to using both brake levers.
During normal riding the brakes work so well that the minor differences can not usually be felt by inexperienced riders. In those conditions, you're (hopefully) nowhere near panic braking mode, so the excellent calipers and discs combined with the booster pump stop the big beast very well. But the differences are still there.
The correct technique is to use both brake levers all the time, modulated as to the current conditions. Sure the front brake provides maybe 80% of your stopping power, but why just give up any of that extra 20%?
The only exceptions may be in excessively slippery situations or tight, slow turns where adding front brake can seriously upset the bike (and rider, for that matter). 99% of the time it won't really matter to most riders, but during that 1% panic stop, I want to know
that I'm slowing down absolutely as quickly as possible under the given conditions. Saving an extra 10 feet or fraction of a second could mean the difference between an annoyance and a really bad day
. That's not something you can just call up when you're in imminent danger of a collision. You have to practice it every time you ride. I've had situations where by the time I consciously recognize a threat, I also realize I've already started braking or swerving away from the danger. That muscle memory can save you one day, but not if it isn't completely natural and normal.
Technology is wonderful, and I'm continually impressed at what innovations BMW brings to the marketplace. But a German engineer isn't riding your bike, you are. So you're responsible for learning to ride it well, and safely. Sure this is a potentially dangerous pastime, and we all accept those risks and try to mitigate them as best we can. At best, using only one brake shows an incorrect understanding of the physics and forces involved in riding, and at worst it falls somewhere between laziness and a lack of riding skill.
Please note one exception. I know there are a few folks who cannot use both brakes well due to specific physical limitations. For them I'm glad the Integral brakes work as well as they do, as it offers them increased safety over a conventional braking system, though they're not quite getting the full benefits. And anything that allows you to ride instead of being stuck in a cage is a good thing.
So while it may be "OK" to use just one lever, it sure isn't correct.