Hi all,
I've been taking Mass aminos for close to a year now and I was thinking of changing to Density for a while just to mix things up.

If my overall objective is build muscle/lose fat (but build more than lose) will this switch be OK? I just wasn't sure if Density is targeted more for contest preparation and not really for size building.

I would do Density if you were leaning more towards getting leaner. Since you have decided that muscle mass is more important, I would stick with Mass Aminos at every meal... That is, after all, one of the 2 best kept Beverly Secrets!