So the stock muffler is strait tru!

So Im cleaning my FZ10 today after a nice mtn ride and I look down the stock muffler and it is a strait thru design! So how much louder could a after market slipon muffler be? I like my cross plane to be heard better like on my 09R1 I had with slipons. But I cant believe a slipon would be that much louder than a stock muffler, Im thinking maybe keeping the stock muffler and get the mid pipe? I know these bikes are still new out there. But Im not going to make a move on exhaust till I get some good info . Any one know who just changed out the midpipe and kept the stock muffler?