The way I see it, without being privy to insider knowledge or medical records, is that Iginla is the safest bet to draft a top 6 player. Not the most talented, strongest or biggest. Just a good player with a great shot, intensity, professional mentality and work ethic. You can question his ceiling, but he's also one of the youngest in the draft and the next 6 months could see a massive leap in development, just like Sennecke in the second half of the season (although his was understable with adjustments to his growth spurt).
Demidov has the highest ceiling, and he has to be the pick at 5 if available
Lindstrom and Sennecke have high ceilings, but they come with higher risks as well. I agree with a poster saying that Sennecke always does the same deke, although that's just highlight packages... I admit to not seeing full games of his.
So it boils down to what the consensus will be at the Habs final draft meeting. Will they take the safe approach, or swing for the fences? If Demidov is gone, the safe pick would be Iginla. The obvious choice is Lindstrom if he's there at 5. If not, will they go for Sennecke if they feel development will make the question marks go away?
Aside from Demidov, my head tells me Lindstrom, but my gut still tells me Iginla. For me, he has that "it" factor.
That being said, I would be happy if we draft any of them.