I know this is a very subjective question, so maybe we can use Stalin as a reference. Would Lenin have been as bad as Stalin? Was Lenin as opportunistic as Stalin? Would Lenin have purged as many people? Could the USSR have survived if Lenin theoretically controlled it for the entire 20th century?
I'm reading a book on the Soviet Union, and it seems like Lenin wasn't that bad. The NEP allowed markets in farms and small businesses, and he advocated total free press (but was blocked by other members of the government). So what y'all think?
I'd have to be really frustrating and say this isn't really an answerable question. If we were to simplify it and just compare Lenin to Stalin, the thing is that Lenin and Stalin were operating in very different times, under different constraints. We don't know what Lenin would have done if faced with the threat posed by Hitler after he wrote Mein Kampf. Lenin approved the use of terror as a policy. And the biggest thing I would take away from NEP is that Lenin was capable of bending his ideological principles in light of immediate circumstantial constraints.
I don't think this tells us whether he's "better" or "worse" than Stalin -- rather, it says we can't possibly use his known ideological positions to predict what he would have done if faced with, say, Hitler's invasion. And as far as I know it's not sufficiently clear what he would have done about the famous industry vs. agriculture debate as time went on.
As personalities, I see many troubling red flags in Stalin's biography that are....not necessarily absent in Lenin's, but different. But I wouldn't feel comfortable judging one as "better" or maybe more sane than the other. I don't think those kinds of diagnoses are possible. Lenin's writings show a level of education, intelligence, and discernment that Stalin's arguably don't, but Stalin had his own form of -- for lack of a better word -- genius that helped him achieve his goals (albeit to the detriment of everyone else). In any case, I see little evidence for moral restraint in Lenin's views, sufficient to posit that he would have stopped short of doing the kinds of things Stalin did out of any moral compunction (that Stalin obviously lacked). Whether he might have come up with policies that might have met his goals with less loss of life is just unanswerable because it's contingent on so many unknowns.
You might be interested in the new biography of Stalin by Stephen Kotkin, and the biography of Bukharin by Steve Cohen, which argues that Bukharin was actually the "better" alternative that was missed.