CB7 was used as a basis for host-guest benchmarking (including on binding of guests with adamantane and aromatic ring cores) since some of its properties and characteristics made it a convenient host both computationally and experimentally . Four insights and challenges for CB7 are described and some may be transferable to a clip type cucurbituril. The tight exit portal of CB7 makes it difficult for guests with bulky hydrophobic cores such as adamantyl to fit through the portal and hence lead to convergence problems. The timescales of wetting and dewetting events may be large compared to typical simulation timescales. In CB7, when gradually decoupling a guest there is a large fluctuation of waters in the host cavity. The latter occurs when the guest is partially decoupled and may also lead to convergence problems. (3) Experimental and computational binding thermodynamics are sensitive to the salt composition and concentration (for buffer conditions). ( ) Guests with formal charges can pose challenges for binding free energy calculations (Section 3.1).