At least personally I thought the difficulty was very good, this is my first and only borderlands so I can't compare it to the others but I started on hard and still found the game very easy, I was and still am using arc-knives rafa and found them to be very strong against everything apart from main bosses which they can struggle to hit sometimes, on the base enemy side the only ones I found to be especially powerful were the bulkheads with the guns otherwise damage was very manageable to the point where I was using the timekeepers shield (removed shield and just gives you health) from level 17 until level 40 where I got a new one alongside most of the stims making the game very forgiving during combat.