Integrated tube amp vs Tube amp?

There are 2 schools of thought on preamps:  Preamp should "add to sound quality" and "preamp should be invisible".  

Integrated tube amps usually are looking for the 2nd path to success.  So if you're in that school of thought, integrated tube amps may be the way for you to go.

If an integrated amp uses a 12au7 for the preamp stage, which is pretty common, it's definitely NOT going to sound invisible. 

An additional advantage of going with separates is you can have the power amps be monoblocks. This can allow you to place them closer to the loudspeakers, allowing for shorter speaker cables. With tube amplifiers in particular, this can really help improve bass impact and the ability to pick out vocals. When you have monoblocks the amplifiers won't share power supplies either- this can result in lower intermodulation distortion, which causes the system to sound smoother and more detailed.

I guess I am asking will I get more performance ,for my money, by getting just tube amp?

     Yes!

OP, you have a nice Mac Stack with a tube pre-amp. I say go for the Cornwalls and get that itch scratched. but don't throw away your Tritons just yet. 

Sharing my history I moved on from a Rogue Audio Cronus Magnum II into a foray of separates- 

(2) rogue audio tube preamps, rogue audio, parasound and pass power amps, cary audio tube preamps.  

truth be told I miss the sound of the Cronus Magnum integrated.  The only thing it was ultimately missing is that last ounce of speed and dynamics compared to my current tube preamp / solid state amp.  But the overall sound was often simply gorgeous, something hard to find regardless of your system.