Looks good so far.
On my machine I filled my gantry tube with high density polyurethane foam. I tried to do a before and after comparison of how it affected vibration and the numbers I got did show it affected how the beam responded to an impact. I still haven't cut any aluminum with it so I cant say definitively that it works well for that. But, I did use Clear Path servos on it and in their auto tuning routine, they assess the stability of the mechanical system they are attached to. The parameter the servo's came up with indicated my frame was very stable. So I think I can say for sure that filling my gantry tube with foam had a positive effect on stability. The foam cost me about $40 and an hour of time. Seems like it was worth it.