Grumbleweed_
The disadvantage of being a Sonar user is a lot of what Reason scans is unusable outside of Sonar (Sonar has a lot of plug-ins!). If you are used to using the bundled software then Reason is going to frustrate you.
Grum.
Yup, there are some Cakewalk plugins licensed for use only in Sonar. For example Blue Tubes FX, True Pianos, AAS Cakewalk Session products, Overloud Breverb and TH3, etc. But there are some that will work fine in other DAWs.
These will work, for example: Boost11, Channel Tools, Dimension Pro, LP-EQ, LP-MB, PX-64, Rapture Session, Studio Instruments, Session Drummer, TL-64, TS-64, VX-64, Cakewalk Sound Center, Tone2 BiFilter2, Celemony Essential, Addictive Drums, etc.