I like the ability to use objects (and thus functions which return objects) as lvalues. A bit of my old C++ days sneaking up on me. But I won't use that until Perl6 when you can actually set a function to be the "set" routine, and a function as the "get" routine. I like the syntax of $obj->foo = 3, but I definitely need to be able to easily (that is, with little overhead) trap that to do something else with it - whether that's validate the new value, set a marker for change (that represents a dirty object for persistance), or send out events to listeners. Or even, heaven forbid, change my underlying object such that foo now represents something else. About the only thing I like about Perl 5's lvalue attributes is that they were something that taught Perl6's designers what was really needed :-)