if stock falls to 2-3 and stays there for 3 years you will lose all the premium on warrants. 100% loss. If you own stock them you lose much less. Buying warrants is cheaper if you are sure that you are going to make $.
One further distinction. As a warrant holder you would not participate in any shareholder votes. Not an issue for retail players whose votes would not have significant influence anyway.
The biggest con would be if PPS doesn't appreciate significantly. For example, say the PPS topped out at $7.00.
IF you bought a share today @ $3.50, you would have 100% ROI at $7.00, whereas the warrant you bought today would only bring you about 40% ROI @ PPS of $7.00 ( $7.00 less $5.05 excercise price less $1.40 warrant cost gives $0.55 ROI on your $1.40 or about 40%).