Cory, I use all three of the coverings you mentioned above in addition to silk. Slikspan is not as tough a covering as Monokote, Koverall, or silk. However, some of my lightest, best finishes are with silkspan and dope. Silkspan can be sanded after a coat or two of dope has been applied, but care must be taken not to sand thru on high spots like wing ribs. I usually only use Monokote on my models for a fast and easy finish that's quick to repair. I fly off a grass field and have used Sig Koverall or silk on the undersides of my wings as an option with silkspan on the top of the wing. It gives me a tough underside to help from getting grass, stick, punctures and still have a light good looking finish with silkspan on the tops of the wing.I have not encountered any problems with twisting of my wings doing this. Each covering has its pros and cons. Good quality silkspan is tough to come by these days. I also cover my fuselages with silkspan and dope. It does add strength with a minimum amount of added weight.......Gene