Armor 2.0 lets you choose a frame and fit compatible plates. The frame determines the structure and its bonuses; the plates determine armor behavior. Treating all armor as the old launch-era system misses both choices.
Frame first, plates second
The original preview described Medtech, Specialist, Saboteur and Mercenary frames with different slot counts and tradeoffs. That is a historical starting set, not a complete current list. Update 3.6 added Vanguard and Survivalist through Crimebonds. Inspect the frame's own restrictions, downs and movement effects before assuming you can insert any plate combination.
Read the recovery behavior
The Armor 2.0 preview names Resistant, Adaptive and Impact plates. It specifically describes Impact plates as fully regenerating even after destruction, with no inherent damage reduction; regeneration delay accumulates across plates. This explains a tradeoff, not a promise that an all-Impact setup is best. Read the current tooltip for your other plates and supporting skills rather than applying one recovery rule to all types.
The newer frames have different jobs
The 3.6 description presents Vanguard as aggressive: two Resistant plates, no speed penalty and trauma recovery through defeating enemies. Survivalist is defensive, supporting First Aid Kit healing with five downs and three flexible plate slots. These are documented frame descriptions, not measurements of current best-in-slot performance. Compare the actual menu before investing around a specific number.
Diagnose why you go down
As a practical test, change only the frame or plate setup first and keep difficulty and skills consistent. Note whether you fail while recovering armor, crossing open space or moving loot. More protection on paper may not solve a movement problem. Check your skills and weapon perks together with the armor, and use quieter HEAT retreat windows for objectives. The shooting range alone does not test survival under enemy fire.
Sources
Based on official documentation. Gameplay advice is editorial unless a test is explicitly documented.