I bought the 5 gal (5510A) and, even having been told countless times how much of a difference it makes, I was honestly unprepared.
I bought the compressor before my Thunder Laser even showed up, but hadn’t connected it until very recently. I was trying to cut through 1/2" (12mm) plywood and no matter how slow or how many passes I took it just ended up charring the hell out of it by the time it got all the way through - it looked like I was using a acetylene torch, not a laser.
I had conceded defeat and was putting my jacket on to go to the hardware store to buy some 1/4" instead when I saw the real compressor and thought, “meh - I’ll just give it a go. Couldn’t hurt.” 7mm/sec, single pass, clean cuts all the way through, no smoke residue on either side. It’s a completely different machine and I’m kicking myself for not having done this sooner.