Bio-Fuels? Yay or nay?

This is a broad topic, but what is your opinion on bio-fuels. I am trying to decide if this is something that should be investigated or if it is a dead end. I don't have a strong, well informed opinion either way at the moment.

My rough thoughts: pro:

• maybe a solution for certain transportation modes where battery technology might not quite cut it: shipping, long-haul trucking, aviation
• carbon neutral by closing the cycle
• potential for carbon capture (storing some of the converted carbon e.g. the char residue and using it to fertilze ground and make it carbon negative)

contra:

• conversion of fields that were previously used for food
• danger of companies using old forests etc. to convert to biofuels.
• it seems to be sometimes pushed by the wrong players (e.g. car manufactures, petroleum companies): this makes me suspicious