Yup,

UC is easier to apply and less prone to wrinkles but it is more sensitive to heat settings. It's hard to overheat MK unless you really want to melt it. Because of the single bonded layer type of film it is, it adheres better, is more tolerant to varying temperature, more prone to wrinkles but also has more shine. UC is great when learning I'd say, the fact that you can heat it and reposition it with no adverse effect is great. Once MK is stuck, it really is. Pulling it off is not much fun.

If there is such a thing as a "good filler" for covering to adhere to, Balsarite film is probably it. Using a typical light wood filler (spackling type stuff) is actually terrible because it doesn't allow the adhesive in MK (at least) to create bonds - kind of like polyester resin over epoxy, doesn't work. Hence the need for "glue coating" wood fillers under plastic film. However, some people use spackling filler in solution (e.g., polycrylic) to close balsa grain (and glass weave) prior to painting.

David.