They work well with decalfix softening them or the Vallejo Decal products and providing you clip them as close as possible they are almost invisible once applied and treated.

Here's some on a recently completed Panther Conversion for the 653 Heavy PanzerJagers. The smaller crosses are very handy for Panther models as well as other small AFVs. (his sheet has 3 different sizes)
On painting table last night.
4 Vampir Panthers (IR Equipped Panthers)
2 Kugelblitz (AA Pz IV tank)
1 Hanomag command
1 Mobelwagen
I based a platoon of German Mountain troops too.
Happy Days, Keep Painting. FIL