Needs more horsepower.
Requires more attention to load and balance.
Much more finicky with regards to prop specifications, engine height and trim angles.
Designed for use in calm water, running a chop can present problems.
More wetted surface means more friction.
Tunnel takes up planing surface, provides less lift on plane.
Reshaping water takes energy and usually causes aeration
so a cupped 3 or 4 blade prop is needed to get efficient bite.
Power jack plate needed to fit engine height to conditions.
Chop lifts the boat out of the water, pushes air under the hull and tunnel loses prime.
Slower by 10-20% than non tunnel, reverse is a pain, drafts more as well, ride suffers....
However, if you wanna run skinny than a tunnel is needed as you'll run shallower than you'll float. Places like Bahamas and TX all are tunnel fans...
Hope this helps?