The correct answer to this entire question is "yes". Use whichever tool encourages you to adopt proper configuration management.
Yes, there's a gap that the current crop of CM tools don't address (and why we see new versions of capistrano clones with a bit of system management sprinkled in) but the three major tools right now - Puppet, Chef and CFengine are all at a state where they address 95% of the use cases for system management and automation.
It's not so much what I consider to be missing as what others don't seem to be finding in them that encourages them to bolt on functionality into "incompatible" tools:
Yes, there's a gap that the current crop of CM tools don't address (and why we see new versions of capistrano clones with a bit of system management sprinkled in) but the three major tools right now - Puppet, Chef and CFengine are all at a state where they address 95% of the use cases for system management and automation.