Pros:

Amazing attention to detail.  The levels are pretty much exact recreations.

Actual music and gameplay mechanics, like platforming, the bouncing crates, the timed TNT crates, and the sound effects to go with them. 

Great feeling of nostalgia was almost overwhelming during the first few levels.

Cons:

The level 3 bug.  Can't give it a 10 because of that.

Conclusion:

Amazing experience.  Mods like this are the very reason I game on PC more than consoles these days.

Pros:

Great model, just like the real thing.

Looks great in both 3rd person and 1st.

It's either him, or them, and the way he sees it, might as well be them.

Cons:

The lighting on his clothes can be weird at times, making him look wet.

On a similar note, his eyes can sometime reflect too much light, giving him this "cute puppy dog" look, unbefitting of a man like John.

No voice or name/portrait but no points deducted because in my short time on this website I've found that most models don't have these features.

Conclusion:

Almost a perfect model.  Minor imperfections will definitely bother the OCD-type, but I plan to use this for the foreseeable future.