Pros : The best thing about the pins is that they are usable in both foil and lead work. For foil I use them to hold the piece together - for lead work I use them as spacers -
Cons : They are pins - so you can't ask for too much but it would be nice if they were a millimeter or two longer...
Other Thoughts : I also use them to create block areas on separate boards to hold cut but not yet ready for use pieces...