This is the first time I heard of a Jet li mod. Hmm. Sounds good. I enjoyed both MP2 and PoP. I also typically don't have a problem with shorter but sweet games. Heck, I play arcade games all the time, and while short, they are made that way so that you'd easily replay them over and over again. I find that I tend to play games that are long very few times, if I even bother to repeat them. Of course, that does depend on the game. I don't think any other adventure game lured me to replay it time and time again like Shenmue II did. Normally, they don't have a bunch of arcade games, gambling games, and/or plenty of secrets, items, and easter eggs to find(certain ones even take you to totally different involved tucked-away portions of the game). Still, they're fun all the same.
If it's an action game, or an adventure game, I typically expect the average playtime to be between 10-15 hours. That's what they usually are, and that's a lot longer than they used to be.