I think I played Half-Life (the original) about 5 or 6 years ago, and it was still just absolutely amazing. They nailed the atmosphere of that game. Just creepy, and fun. It's amazing how well it holds up.
I definitely wanna pick this up eventually, but I refused to buy "Early Access", even on sale. I honestly don't think Half-Life needed a "touch up", and I wonder if it might lose some of its charm, but it's a great excuse to play through arguably the greatest shooter ever.