I am in the same situation as you. I've always had the foot attached. I am ordering a new main within the next few weeks and narrowing my choice to manufacturers and cut (cross-cut vs. North Radian or Quantum Fusion). But one choice is clear. I will definitely go with loose footed. To put it in perspective, the vast majority of jibs are loose footed. The reason why we still use a boom is because it is impractical to sheet a main without it.
1. Better sail shape control because there is no foot
2. No flattening reef needed
3. Easier construction because a shelf does not have to be made & slides do not have to be fitted = reduced cost.
4. Easier control because you don't have to fight sail slugs on the boom
5. Easier furling and reefing because the foot is free.
1. A tendency for foot flutter. Corrected with a foot line.
Sabre 38 "Victoria"