Dark Souls II has Soul Memory, which means you'll be matched with players of higher and higher level whether you level up or not. Since the game has significantly weaker hard caps (many stats will give noticeable improvements all the way to 99, unlike Dark Souls where everything turned to shit at 40 or 50), fighting a level 800 player with a level 150 "meta" build will be extremely difficult, because they'll be fast-rolling in Havel's Armor with a buffed Chaos Blade, 2200+ HP, double your stamina and all the magic and buffs they'll ever need.

The katanas are even less balanced than in Dark Souls 1, since Counter Damage is automatically boosted by 50%. Kicking is gone and replaced with Guard Breaking which will never hit any competent player. There are no whole eye orbs, so you need to farm for them. Invaders can't reach hosts in some places. There's an invasion time limit. You can no longer turn any direction and attack after rolling or during a combo. Toggle-escaping and dead-angling, while probably unintended, vastly increased the depth and balance of the game for experienced players, and there's not any replacement for either of these in Dark Souls II. Invaders can't heal, can't summon and are no longer safe from enemies, massively stacking every invasion in the host's favor. For me, the netcode was even worse than Dark Souls. The game is also much slower-paced in general, with attack recoveries, stamina regeneration, rolls and parries being generally slower than in the first game, and these things make players more defensive which slows the game down even further. This vastly decreases the intensity of the PvP in my opinion.

Dark Souls II is more accessible because backstabs aren't quite as bad, but after I spent enough time to become good at Dark Souls 1 and decent with Dark Souls II, I enjoyed Dark Souls 1 a lot more.