I have had a partially used with the air squeezed out bottle of Legacy Pro L 110 for about 5 or 6 years now. Works exactly the way it should.
This is good to hear. We don't know how long HC-110 is going to last yet because the new, less viscous, formula hasn't been around long, but L110 has been around for a while and it, too, is less viscous. That suggests that the more watery liquid hasn't completely lost its impressive life expectancy. I have an unopened bottle of L110 from when I bought some Legacy Pro products to test.
As for the comparison of the three, I have some decanted Ilfotec HC that has been in a half full bottle for 8.5 years that I just used at 1+47 to develop a short roll of HP5+ and the resulting negatives looked perfect to my eye. In fact, I have three additional small bottles that are full. Unopened, HC is supposed to last indefinitely, so I figure my full bottles will last at least that long if not longer (haha). I dilute directly from concentrate, but doing so makes accuracy a little less certain. To make 300 ml of working solution requires 6.25 ml of concentrate. I use a 10ml syringe which is graduated in increments of 0.2 ml. Diluting it into an intermediate stock solution defeats the long shelf life, which is a characteristic I'm not willing to sacrifice.