It's all subjective of course but in a nutshell, sound and feel. It allows me to use my tube amps with speakers or IRs with Boss quality delays and verbs.. It allows me to use my modelers with the 30 watt power amp. It's become my freakin studio Swiss army knife.. I love Helix rack, my Axe Fx, myQC as well as my Marshall, Peavey Invective , SYN20ir etc etc.. They all work very very well with the Boss TAE core