it looks on the ground, it will fly good
No. What we're saying is it will look good if a true master builder built it. Only the design of the plane and the conventions it was built by will determine how it flys.

For example, here is the caveat I include with the planes I build for others.

This airplane is not a toy. It is a fast, extremely maneuverable radio control
aircraft. Purchaser shall determine the suitability of the product for his/her use, and shall assume all risk and liability in connection therewith. This plane was built according to the manufacturer's instructions or with modifictions following current R/C building practices. The glues, materials, and hardware were either supplied by the manufacturer or were substituted following the same R/C building practices. This plane is warranted to be airworthy if flown within the manufacturer's recommendations and in a style typical of this type of plane. No other warranties or quarantees are suggested or implied.

Dr.1