Going out of town for several months leaving the Alexia with the wife, Gaggia as my traveling companion. Testing it today, found out the grind for the Alexia totally choked the Gaggia, using a SJ Doserless, Dialed in the Gaggia in by going coarse by at least 5 steps, why the difference?

I think its more about the basket difference as opposed to the machine. My gaggia knowledge is lacking, but I don't imagine its the same size as your Alexia so you are probably not using the same basket, right?

Even on the same machine, switching between a VST and another basket requires a grind change so this seems reasonable.