All it takes to tech into cloak is the 600 metal and sufficient energy (~500 metal). There are many cases where cloak is straight up beneficial, and people should use it more.

Especially strong in team games cause your allies don't know your troubles at a glance.

Other cloaker facts: units with personal cloak won't drain their personal cloak energy when covered by area cloak (because they take the area cloak instead). Taking the area cloak instead of personal cloak also can decrease their Decloak radius.