I personally like Jackson as a prospect a lot; it certainly takes a certain willingness for risk though. He's an incredible athlete with great arm strength and he's a much better passer than he's given credit for. If you adjust for drops, his completion percentage is ahead of Darnold and on par with Rosen/Rudolph (Mayfield is wayyyy ahead of the pack). And despite not being a traditional pocket QB, Louisville's offense has more pro concepts in it than what was run at USC or either of the two Oklahoma schools. If you watch Lamar, you certainly see him sail some passes high, but you also see him make a lot of "NFL throws", throws into tight windows, and just some absolute dimes down the field.
I like Rudolph as a guy to target in the 4th round, but nothing higher than that. He just doesn't really have any strengths. His arm strength is probably below average. His ball placement is generally below average. His athleticism is below average. He doesn't really show the ability to work beyond his first read very often. He's just a middling prospect, like a slightly better Nathan Peterman from last year.
If Buffalo can't get one of the top 5 QBs (in my mind, Rosen, Darnold, Allen, Mayfield, and Lamar; not in that order), I wouldn't bother taking one at all until around the 4th round. There's plenty of worthy projects to take after that top 5, but they're all significantly worse prospects IMO. I don't think anyone outside of the top 5 projects as a starter in the NFL; I'd give Rudolph, Lauletta, Woodside, and Falk a snowball's chance at least, but they're far more likely to end up being backups.