I just aligned and leveled my 504 tonight and did post-verification with the Versalab laser tool. I shit you not, dot center from top of column all the way down. Amazing enlargers - machines actually. This is how professional tools used to be built. Definitely the best I've ever used.
Anyone have suggestion for notchy column feel though? I figure it might need some grease on the column guides. When I say notchy I mean one can feel the rollers/surface interaction when adjusting height/focus. It's not the end of the world but it makes grain focusing a bit easier if the feel isn't gritty.
Stop worrying about grain, resolution, sharpness, and everything else that doesn't have a damn thing to do with substance.