I just completed NYM Hardcore last night and it was one hell of a ride. I just want to make a club where people can post their NYM Hardcore times with a picture taken after. Goodluck for all others going for this dreaded achievement.

My hat is off to you sir! I've beaten NYM and I've beaten Hardcore individually but NYM Hardcore has defeated me twice. This is one achievement that I may have to let pass by.

Congrats to you and anyone else who goes through with this. 
 
It doesn't seem impossible if you're familiar with the spawn points and know where the pills are but there are one or two sections that i know would give me a lot of trouble, specifically the part in chapter 6 where it starts you off in this horrible position in the office cubicles next to this side wall. I've yet to successfully beat that secion in one go from lack of cover and ammo and getting flanked to all hell.

I would say what makes it hard is the unskippable cutscenes and the glitches you can run into on a hardcore playthrough. I got my achievement on my 9th playthrough. I would run into 1 glitch every playthough such as skipping the cutscene where the swat team is breaking into the train (Freeze) or switching to a new weapon just before a cutscene that would make 2 of my guns clip into each other (Can't Shoot). I would say your best bet is to know the spawn points, painkillers and practice on certain parts you die on. I never used shoot-dodge (Bullet Time). In most cases you will need to RUSH your enemies first. If you keep at it I'm sure it will get easier but if your on your 20th attempt and still getting rocked then maybe it's time to let go.

If only they had a save point at the disc swap or maybe something like Dead Space 2's save system with 3 saves only.

Got it today on my ninth attempt also. 90% of the time I spent in gunfights I was strafing and flanking enemies, abusing BT to land headshots. You really want to blaze through the first half at least, focusing on killing as efficiently and quickly as possible to build a time buffer for the last two chapters.

I'd like to try this but can't be bothered with the damn unskippable cutscenes