Both solid and mesh bags are useful tools to have in your carp angling armoury and the choice between the two methods is dictated by the angling situation.
The solid bag method with a small balanced hookbait is almost a ‘cast anywhere’ guaranteed presentation. When packed correctly, a solid PVA bag will never tangle, and always creates a consistent trap. You can add all sorts of PVA-friendly liquids and powders to boost the attractiveness of the parcel. In my own experience, the only limiting factor occurs when fishing in very deep silt. Sometimes the whole PVA bag can sink so far into the silt that the benefits are largely lost.
The single greatest thing about mesh bags is their wonderful convenience. You can put almost any dried bait in a bag, tie off a tight parcel and hook it on. This amazing versatility and speed means that they are used to great effect by anglers all around the world. From a tiny mesh bag of boilie dust threaded on to the hook to stop the hair tangling, to a big PVA bag hooked on and lobbed out to create a one-mouthful trap, mesh bags are a one stop hassle-free solution to having freebies next to you hookbait. With larger bags you need to make sure you feather a cast just before the lead hits the water to maintain good presentation with both lead clip and helicopter arrangements.