Nilbog tends to be hardcore about making sure the game mechanics are classic. but this is 2015 and everyone has broadband internet / laptops that were supercomputers by 1999 standards / guides for every single encounter in the game / etc, which makes the game not feel very classic despite having classic mechanics.
there have been very few instances where Nilbog et al have implemented non-classic mechanics in an attempt to make the server feel more classic. the biggest example of a change like this is variance on the spawn timers of raid mobs. another example was how they nerfed the Fungus Covered Great Staff and binding in Timorous Deep so soon after launching Kunark -- i think TD binding got nerfed on P99 within a day or two of Kunark launch, whereas on live you had a much longer window than that. the difference being that back in 2000 when Kunark first launched, no one realized how OP firepot binding was or that it was going to be nerfed.
so classic mechanics /=/ classic feel