The Monza arrived two months ago. It's much tighter sounding with the Coda on top, than the GR and it's 350watt internal amp. Difficult to say if it's the amp or the speaker, most likely both
The GR seemed like it had more bottom, but it was also quite blooming. The Monza is very articulate on the B string (I only play 5 'rs these days) and really makes my basses sound as different as they are

The Monza sounds better from anywhere in the room, the GR had its limits.
I much prefer the Coda/Monza setup to the GR.
The only thing I miss is the stupid light weight of the GR. But the Monza cab has the better form factor for carrying and loading.
Never tried the Monaco. LFSYS are in the UK, I'm in Norway.....but I really can't say enough nice things about Steve and LFSYS. Great experience dealing with him.