External insert, worked flawlessly first time ever for me...my SonarX-producers were intermittent with this feature, not sure what changed but I know something did...I can even use my Nebula plug-ins (huge cpu demand but by far the best for hardware emulation outside of UAD) and with the latency (sample) compensation it works quite well...
 
Kudos to the bakers that cannot be an easy thing to pull off.

I second this, Thanks bakers!
 

Hmm, I actually started using external insert quite a bit in Sonar X3e when I bought some used FX units several months ago.  FWIW, I always had pretty good success with it :)  Nice to hear it's working well for you in Platinum.

Yes I tried it for hours in X3 but never had any success, was a major drawback for us since we have tons of vintage boutique pieces of gear in my rack (Pultec/LA2A/REDD47/etc), since I never got it going I finally gave up, first try in Platinum and was pretty much as advertized...