I couldn't be more happy about my purchase. I previously had the Xbox version and loved it. The flashlight 'problem' never bothered me, i loved it, it added a lot of scares for me. Having said that, the decision to replace the flashlight with a light on doom guys armor is enabling me to play in an entirely new way. I'm more reckless, I play more like I did Doom 1 and 2. But its still scary! Also, the flashlight change (as well as a few other issues) have been heavily exaggerated by passionate fans. The flashlight that I am using stays on for about 20-30 seconds before dying, then takes about 7 seconds to recharge. Sounds like a lot of light but in-game you'll find yourself running it dead at the most inopportune moments. It really is implemented well.
The graphical enhancements put this miles ahead of what I played on the Xbox. I honestly didn't expect this much of an improvement. Keep in mind that I never played the PC version, though. I also noticed almost immediately how much more of the game I had been missing on xbox. Game runs incredibly smooth, too.
Checkpoint system is admittedly tedious, but I'm hopeful id will allocate some of their time to make it shorter/make it optional. And although I like the flashlight armor just as much as the original, it would be nice to have the option.
In my opinion, this is a must buy for any console gamer whether you have played the original or not. I cannot speak for PC gamers, though.
Anyway, thank you id software. I couldn't be happier.