To me being a boom or bust is kind of a plus for a QB, because the worst you can be is mediocre once that rookie contract comes to an end. I would prefer for whoever we draft to be either great or horrible and for us to know relatively quickly so we can either invest in him or move on quickly. This is part of the appeal with Love for me. The things he needs to improve are heavily coaching based and I think we will have a good idea of where on the spectrum he will end up pretty quickly. For example - if you draft him and he's not ready to start by year 2, this is a red flag and you might start looking for another one. If 2 off-seasons and 1 in-season period are not enough for your coaching staff to get him ready you either have made a mistake with the draft pick or with your coaching staff and I do have good trust in the coaching staff so...
For me the tiers are more important the the specific ranking... I rank players within a tier very similarly and even though I would have preferences within them, I don't feel strongly enough to argue one over the other.
Tier 1(sell the farm for him - i.e. multiple 1sts, multiple day 2 picks, etc)
Tier 2 (trade a significant asset for him - i.e. a future 1st round pick)
Tua(if I have medical guarantees he'd be alright health-wise)
Tier 3 (trade a medium level asset for him(i.e. a second, a third...) or take him at #13)
Tua(if our medical staff cannot give you any guarantees whatsoever either way -for example, there were some reports that it might be too early before the draft to tell whether he will be good or not)
Tier 4 (second round)
Tier 5 (third-fourth round)
Gordon(have to do more work on him, might change his ranking)
Tier 6 (round 5-7)
Tua(if the medicals come bad and there is high risk of reinjury/retirement/not full recovery/etc.)
I'm still watching some QBs so that's not my final ranking.