I asked myself that question for a month. The pros:
-using old skis that will now oly be used for urban, so its not like if i screw up then i cant ride this season. i guess thats the only pro
The cons:
-hard to accuratly free mount
-easier to rip out
-no warantee
-could drill through base
so i told myself you only live once so go for it. So i did, and it worked out fine, hopefully all goes well.
if your thinkin of it, i wouldnt for new/good skis, but for something kicking around, giv'r a go.