I would have it no other way. When you hold that assembly in your hands, you will realize how HEAVY 12LBS feel and are when concentrated in a small area. Heavier than the heaviest motorcycle battery. Save about 11LBS, since the new midpipe would be about 1.5LBs, install a lithium battery, and marvel at the tangible feel of weight savings. And also the looks, SO MUCH better.
It is louder obviously than stock, but nothing extreme. And no adverse effect on performance (or gains really, without a flash - maybe a slight top end gain as is).