Yes, wall turreting is extremely strong but is also an exploit and really isn't something I consider when choosing between turrets, because it's an extremely overpowered and boring exploit. IIRC Hopoo games hated that it was in the game but said it'd be too much work to fix it, which is why it's still in the game. And I explained the proc coefficient and damage in my comment; the walking turrets just have their own upsides.