I used to own the Chaconne too, and IMO only its upper mids & treble are comparable to Bell-Ti Plus. In all other aspects, the Bell-Ti Plus wins easily, especially in the low end presentation, increased technicalities, plus comfort and wearability of the shells.
The interchangeable plugs on the Plus are a big plus as well (no pun intended), though I did wish they went with a twist lock system like on the Fiio EM5. The titanium finish plugs on the Plus can be quite slippery, and while changing the plug once, it almost flew out of my hands because I slipped a little.
Sounds crazy, but honestly, I'm more wowed when I upgrade from the Onmyoji to the Bell-Ti Plus now, than when I went from the LBBS to Onmyoji.
The Plus is definitely money well spent for me, and I'm glad I took the pricey plunge, instead of spending on endless sidegrades. Also, the Plus is likely to be the last model release in K's Bell lineup for now, so I'm definitely keeping mine for good.