SWIM's vote: It doesn't compare at all.
It's mostly applies and oranges to SWIM.
DMT hits you hard and fast and is gone before you have time to enjoy it. The long duration of the mushroom trip makes a big difference. You’re given much more time to absorb the experience. With DMT if you start getting scared, it’s over in a few minutes, but with mushrooms, you’ll have hours of the experience to scare the crap out of you
Oral DMT with THH, well that’s a different story, it’s more similar to mushrooms, but we’re talking about smoked DMT here. There is really little that is same.
But if we’re talking about Psilocybe azurescens specifically, that’s also a little different. That mushroom is very DMT-like in effects. It’s almost like a slowed down DMT trip for SWIM. But typically people are talking about Psilocybe cubensis, which to SWIM is very unlike DMT.
With mushrooms (especially Psilocybe cubensis) a very large dose can do things DMT can’t do and visa versa. In some ways DMT is more intense, and in some ways mushrooms are more intense. It’s hard to pinpoint exactly, but some people who use mushrooms all the time can’t handle DMT, and visa versa.