HTML::TreeBuilder can consume a lot of memory as it first builds a representation of the document using oodles of objects. It also burdens the CPU more. HTML::TokeParser on the other hand parses the HTML input stream as it comes along, reducing the overhead quite a bit. HTML::TreeBuilder is easy for a quick oneshot script, or nice when you intend to do heavyduty transformation or mangling on the input document's structure, but not a good choice to build an all purpose tool on top of.

Makeshifts last the longest.