[Ironbutt]

I've seen them since I was a young boy but never handled one. They struck me as cheesy and I never paid any attention to them.
This thread got my attention, particularly the light weight part. As I looked around on the web I see a lot of favorable reviews. I like carbon steel for it's ease of sharpening but it rusts easily. I just ordered 2 #8s in carbon steel. 6% discount for 2 plus free shipping. I posted a question on artful bullet where there are several very knowledgeable metallurgists about phosphating as a rust preventative. If one of the guys tells me there's no downside I think I'll try that on one of them.
Since I lost a fair portion of my left thumb I'm not a fan of fingernail grooves but that's not a deal breaker. I can turn it over and use my index finger or open it left handed. Flippers have really spoiled me.
The low price and 1.6 oz. makes it attractive as a backup or something to hand to a friend when they need a knife.

It's a little hard to notice in the pic, but on all my Opinels I sand a notch in the handle where the nail nick is to make the blade easier to get ahold of.

When you first get them they're usually very tight. Oiling may help a little, but to really fix it: Remove the lock ring & spread it apart to make it easier to turn. While you have the lock off, you'll see a heavy steel ring that's holding the pivot pin. Take a large standard screwdriver & pry that ring apart until the blade opens easily. You can also use a hefty pair of lock ring pliers to remove the lock & spread the pivot ring. All this takes about five minutes, but makes the knife much easier to use.