The 1" lift in the rear is a matter of preference. Some riders like it, some don't. Personally, I don't. I set mine up with about 4mm less sag in the rear and it works perfect for me.
Where you will notice the 1" lift most is in the tight, short corners. It's barely noticeable in sweepers. If you coast into the corner as most street riders do (And should), a 1" lift will take less effort to tip in. Remember, there are no free rides. You get quicker tip in but it takes more effort to hold your line. For me, I much prefer to steer my bike onto the choosen line.
Where the 1" rear lift begins to get a bit touchy is once you begin to trail brake into the corners. If you are on the brakes when you tip in, the front is already compressed two or more inches and it will fall into the corner anyway. By gradually releasing the brake and adding throttle you allow the chassy to settle into the corner with around 40% front - 60% rear weight ratio.
By adding another full inch to rear ride height to the two inches or so of compressed forks, you'll find the bike wanting to fall on it's face which can lead to that dreaded Survival Reaction. You'll quickly learn that trail braking and rear ride height has a delicate balancing act!