Are there advanced performance profiling tools (ideally, with a graphical interface) aside from DTrace? Simply put, I'm looking for a utility akin to Windows NT's Performance Monitor (perfmon.exe).  The ability to specify which metrics I want to track (ex. reads/sec, writes/sec) for a given object (ex. Macintosh HD), and ideally, for all or specific processes.

The use case is we have a developer at the office whose MacBook has abominable disk performance.  I/O is bad enough to the point where it may be blocking.  It's evident from Activity Monitor that there's an average of 80-110 IOps, but at this point it'd be advantageous to pin down what the offending processes might be (it's certainly not mds or mdworker).  Although using DTrace scripts such as IOSnoop would probably work, a graphical tool (including non-free) that would provide easier visibility into these (and other) metrics would certainly be preferred.
XCode 4's Instruments is certainly a viable choice that looks as if it'll get the job done. -- you can profile specific processes/agents/daemons and change the active target during the session.  However, developer tools are not a common install on most computers (and it's a large download).