Not much changes with LSD over 700-800 mics, at least in my experiences. I never went as high as 2000, but I hit a few 1500mic trips and they just lasted longer than the 800 mic trips. 700, 800 mics is the magic number for me, though...anything below that and the trip was essentially something happening with me as a spectator, rather than a participator.
Shrooms, at least cubensas, also seem to be fully realized at a pretty good dose, much more than I see commonly reported for trips here. I always eat at least 1/4oz now, dried, all at once. I would say that at least half of the trips I take involve at least 15 grams of dried shrooms, and even then they last only about ten, twleve hours, tops...and that's if I split up the doses.
A half ounce eaten all at once is where, for me, the full fledged trip occurs...doses below this generally tend to be a spectator type experience for me.
Now, don't get me wrong. I have stated on this board that even just five grams of dried shroomage blew my mind apart one time and I freaked right the fuck out just as bad as an LSD freakout, of which I have had four (there will not be a fifth). Three of those trips just scare me even thinking about what went through my head...my spirit. Anyway, like I said, I have freaked right out on a smaller dose (5 grams) after tripping hard many times on 1/2 oz eaten at one sitting.
What I am getting at here is that at low doses, the drugs seem to be more similar than they really are. Go above the doses I listed as threshold and the difference will become crystal clear immediately. LSD and shrooms have almost NO common ground as far as I am concerned.
Doses around 2 grams of shrooms and 100-300mics LSD are purely recreational, without yielding anything near the full value of the drug. 'Museum' dose is a term I have read that seems appropriate, and because of the distance of the actual experience from the user the two seem similar at those doses. A bad trip on 200mics LSD is more like imagining a bad trip...its a bit of self indulgence and paranoia tried on for self-validating purposes.
Get yourself into an ego death involving being on spiritual trial for every thought you have ever generated in this lifetime and before, wondering if you have uttered unforgivable blasphemies against yourself and God, feeling yourself go irreversably insane, with the logic of a brute and the fractured memory of some point to life, now forgotten, ruined, but yet permanently conscious...now that's where you need to be before you can really break through to what matters. At around 800mics LSD I forget that I even took a drug...my mind is certainly not on things like drug effects and so forth because I generally believe myself either already dead or transmigrated and consider any memory of LSD ingestion to be a mental device constructed for the purpose of distracting me from what is at hand, which is usually my own condemnation (guilt is my plague for some strange reason)...and I finally accept what is to come and at that point all of those things that people talk about in their trip reports just go away like a movie that has ended, and I am left with a simple awareness of BEING.
Mushrooms get me there in high doses also, but via a completely different route. COMPLETELY different.
The primary difference between mushrooms and LSD in terms of cognitive reference is the sense of organic vs. inorganic. With mushrooms, even at huge doses, I am aware of my body, even if I think it has died. LSD can strip the body awareness real fucking fast at 1000 mics.
Have a sitter for both, BTW, at those doses. I always do. Incidentally, I have not done LSD in over two years and will not do it again because it now frightens me in a vague, but very significant, way.
Shrooms, on the other hand, I tend to do about once every couple of months, in spurts, maybe two or three days in a given week or something like that. I eat a lot when I do them. Every single mushroom trip I have ever had has benefited me in a very tangible way.