That hasn't been my experience. The stat total level (Armor, Agility, Recovery) are evened out so a Level 1 has the same totals for the three as a level 20. But if you are level 20 and shift your perks around, it makes a difference. For example, max armor and I don't die after 2 headshots with Thorn, or 1 headshot with Black Hammer. Max agility and I get across the map faster.