For many professionals, . After V7, Waves moved to the "Waves Central" licensing system (which many users found intrusive). V7 used the older, more reliable iLok-based authorization.
Waves Complete v7 was a landmark release that democratized high-end analog emulation and introduced 64-bit stability to the masses. While it is now obsolete for modern production, its DNA lives on in every current Waves plugin. The compressors, EQs, and reverbs you use today are largely refined descendants of the code written for V7.
Added to the Mercury bundle, this plugin revolutionized vocal leveling by automating fader movements.
This was a huge deal. Prior to V7, most plugins ran in 32-bit, limiting the amount of RAM a DAW could use. V7 introduced on Windows and Mac. This allowed producers to load massive orchestral templates and mix sessions with hundreds of tracks without crashing.