You are describing something I went through with Helix, and then with Preamp/DI's a little while back.
At the end of the day, any FRFR motor, speaker, system or whatever is just that - it's a completely neutral flat representation of what you put into it.
It's the old adage of sh*t in, sh*t out.. some traditional amps add a colour, a texture and a quality that gives them their unique sound. You need to create that somehow before it hits your FRFR device.
At home, and at rehearsals, I can hear clear differences between different preamp pedals, and different models on Helix - some sound brilliant, others not so much - but for Helix the biggest difference comes with cab sims.