At the start of Season 2 when defense penetration was introduced into the game, primarily to assist lower leveled characters against those with high gear score, it was greeted with open arms. But now at this point in the game I find that the scaling percentages of this stat to be too high. Regardless of the amount of the amount of defenses I have, at no point in time in this game should a light attack be stronger than any characters lowest heavy attack damage. Played a match recently in which a Valkyrie and a Shinobi obviously had their Defense Penetration stat maxed, this is said because I literally watched them shred a Lawbringer to 5% health with only 4 light attacks among the 2 of them. This lawbringer and the Valkyrie had a gear score of 144, but the shinobi was in the 120+ range. It makes no sense as to why, with only light attacks, they were capable of shredding this characters health down. When I entered the fray, the Valkyrie took off to capture a point whilst the Shinobi halted my advance. Me, being a 144 Warden with 75% of the maximum level of defense, landed 2 top lights against the shinobi and his health dropped significantly, approximatelyby half. My blade had all positive stats with defense pen. being one of them. In the time of me faking a heavy, he double tapped me with 1 light and dropped my health by 30%... Like, I really enjoy this game,it's a game that I'm able to retreat to when I'm confused on what I want to play or when I'm worn out in another game, but people always find something to abuse and it kills it for me...
Personally, I think defence penetration should be removed. I mean, it makes it necessary to pick up defence as your main stat on all your armour sets, otherwise you're going to be a glass cannon. I mean, if you go for the other two stats as your main and secondary, you get a whopping minus 8% defence. When you take it as your main stat you only get plus 4%. So to break even you have to take two as your main stat if you want both stamina saving stats (which are pretty much a necessity if you want to fight a raider or centurion...). Add defence penetration on-top of that and you're pretty much always going to be at -10% defence even if it's only their secondary stat. Take defence as all three mains and you'll get a 3-5% boost above normal. It's just stupid.
Alternatively you can completely wreck your character and take the -8% defence for all three equipment slots and then have the -10% or so from the defense penetration to leave you at about 68.4% of your defense. (Assuming the defence penetration is applied after your gear stats, otherwise you've got about 66% your normal defense.) That's closer to half than it is to full! No other stat has penalties nearly this harsh for not taking it!
Defence penetration is just stupid.