I've had the interesting experience of tripping on acid on two separate occasions with only an SLE, and only an ILE (coincidentally, the same two I mentioned in the first post). Now it's better to do it in a group, and have some sort of constant activity going on, but sometimes you can find yourself just tripping balls with only one other person in the room.
With the SLE, I almost don't remember what happened, it was just peaceful. There was some Beatles playing in the background, and we kept losing ourselves in the music, or we'd just keep looking at each other without any awkwardness; we were almost always on the same page (whatever that means), we could communicate complex things with a few words or gestures.
With the ILE, it was much weirder. We definitely didn't plan on tripping out alone in the room, but the club we were at shut down before we expected it to. After finishing all the mutually beneficial activities (getting safely back to the hotel, getting water, etc.) we ended up just sort of peering at each other, like, what are you? Are you dangerous? Friendly? I don't know, but for the time being this is fun, I guess. And then I would lose interest altogether. -- And this mental process happened over and over, there was no resolution. We both felt like we had to stay sharp with the other person in the room, whereas with the SLE we both just let go of any reservations.
My takeaway from this is that at a very elemental psychological level, IEI and ILE are completely alien to each other. The only common ground is the irrationality of our dominant functions - not the intuition, but the irrational aspect of it, is appealing, at least for a short time.
However since we don't live out every day on an "elemental psychological level," pistolshrimp is right, it's not THAT bad.
Also my bad for not quoting properly...