marled
azslow3
burgerproduction
I've also seen it said that Reaper can take Exclusive control of your drivers which can create problems when you try to fire up Sonar.
It can also break your hard disk, permanently destroy your creativity and occasionally steal you music 
Seriously... That is the only DAW with "portable" install option (it does not touch anything outside installation folder). And as any other program, it use the same set of APIs to work with audio drivers. I mean that is least intrusive DAW everyone can try without consequences, yet you mention it as a possible evil. It is not evil, it is Reaper 
And what's about all those "ReaRoute ASIO" drivers that reaper installs? After Reaper's installation I had first to disable all that **** in Sonar and enable my hardware ASIO drivers!
What about reading what you are going to install, before "clicking" ?
That way you will not install unneeded ASIO drivers, malware, spyware and viruses.
a) If you prefer to cleanup after installation, please do not blame software developers for not reading your minds and intentions.
b) Sonar love to prefer new drivers instead of keeping explicitly set by user preferences is outside of Cockos influence
c) unlike ASIO4ALL and some other wrappers, ReaRoute does NOT try to take any hardware drivers under its control. If some particular application is immediately confused when it see more then one ASIO interface in the system, that is again not Cockos responsibility.