The engine is designed to run at the higher rpm and is happiest and most efficient running at that rpm. Takes a bit of getting used to, but it's fine.
Agreed, the Rotax motor is happy at high RPM. Speaking from being a Snowmobile rider with the same motor. If you have seen up close (outside the vehicle) either the Ryker or a Snowmobile muffler you will understand why it's so loud with a smaller or straight pipe lol. I prefer the quiet operation. If you want to be noticed put on some more lights and upgrade the horn if it hasn't already been done.
I have no plans for replacing my exhaust or any other "performance" option as there is just not that much performance you can gain out of these bikes. If that is what someone wants they should probably consider another bike.
The 900 or 600 Ryker has more power than anyone should need. Personally, this 900 ACE or Rally is at a price point that is hard to beat for the cost per smile you get.
Anyway! Welcome to the group! I am a noobie here as well, and from my limited experaince here you are in good company, there are lots of fun, friendly and good people here!