they are completely different pretty much, altho with 4-aco-dmt, the visuals are somewhat DMT-like, in the way a very low dose of DMT will produce visual distortion. the visuals tho, are definitely not as intense, but they stand out more kind of like when you do DMT. for instance, if there were a group of trees, but there was a patch of leaves or moss of a different color, they would stick out very distinctively, almost as if they weren't connected to the trees at all, but protruding from the plane that they were originally in.
When you do DMT, its like every wire or piece of artifact in a room grows and expands, and the craziest shapes form until you're completely surrounded by everything. I've had mirrors expand the entire room, and everyone who was present just wasn't there. I've had the room expand before, so that it was like 10x as big, and it was like I was on a completely different planet in a different time frame. DMT is also waay more intense, in the fact that you really can't move or comprehend much, and you're kind of just blasted out from a cannon, or on a high speed roller coaster. all you can really do is observe what's around you, and try to gain something from the trip, or familiarize yourself with the unique place that it takes you.
I highly highly recommend it. DMT is such a great experience in itself. The short duration allows you to be spun to alternate universes, but you're not there for too long so that it becomes uncomfortable, or causes you to freak out from the intensity.