The fuel injection will allow you to ride at different altitudes without any adjustments.
With the TW you may need to play with the jetting.
My TW is jetted perfectly for where I live: sea level to ~ 3000 feet.
At Moab 4000 + feet I do notice a power loose on the hwy, but I have had no issues with the trails.
If you get the TW jetted for the 9000 ft range you should have no issues.