Well, Not having used X2 very much, I pulled the trigger and purchased X3.  Go Figure!  Selling points for me were Melodyne integration and the Lounge Lizard plug.
 
I am in process of downloading X3 right now.  Can anyone tell me if the Lounge Lizard plug-in has a stand alone mode?  If not, does the LL upgrade have this feature?  I was very impressed with the video demo and I'd gladly pay the extra $75 just for stand alone option. 
 
Regards,
Rich

The version of Louge Lizard bundled with SONAR is a VST plug-in only. All full AAS synths have stand alone versions. FWIW, any VST2 or VST3 synth which does not have a stand alone version can run stand alone with SAVIHost (assuming the plug-in is not locked to a specific host).

scook
 All full AAS synths have stand alone versions.

Scook,
Thanks for the info.  I understand what you are saying, as quoted above.  However, being that the full version on the cake site only indicates that it has additional presets and full access to all parameters.  I just wanted to be certain if it also included a standalone mode. 
 
Has anyone purchased the upgrade and could you please confirm if it has standalone mode?
 
The SAVIhost program looks interesting.  I might give it a try.
 
Thanks!!

The third party upgrades sold at the Cakewalk store are full versions of the products as if purchased directly from the vendor.

Thanks!!