Dxm wins imo.
Neither have ever made me sick, but I just have a stomach of steel.
When I do lsa I try to make myself puke to intensify it a bit but I can never actually puke,
just belch. I normally can't ever get a burp out and putting my finger down my throat is the only way I can belch.
If your gonna eat seeds for lsa try washing of the pesticides if its on them, but I guess thats common sense.
The visuals from lsa are pretty damn cool though, mostly kaleidoscopes and geometric patterns spinning through infinity.
They can both be fun, but I've had a lot better memories doing dxm in squat house parties or just running around town breaking stuff, doing it at raves if I didn't have e, etc.
Dxm is only really worth it if you get to the 3rd plateau, or if you have the powder, other wise its pretty uneventful, weed can change that though.