Fillets and booleans, why?

 From:  Fredrik (FREDRIKW)
Moi booleans and fillets seem to work better than Rhinos. I thought they both have the same modeling kernel?

In the attached image Rhino didn't want to boolean union the consecutive cylindrical walls, and it didn't want to fillet them after i boolean'ed them manually eighter.
- Moi did both without problems (had to make cylindrical fillets though...
(: !!!

- Fredrik