I'm not sure how much detail you'd like, but here goes: One player model is in-game, but it's still far from being complete really. It's missing some animations and still needs some texture work. There are two other complete models in different stages of being skinned. Overall, the player models are still fairly early on in development.
I suppose the differences between HIPR and INS are subtle, or perhaps I have not played enough INS to form a proper judgment. I actually think I'm the wrong person to ask, because my opinion is that there's not that much more similarity between HIPR and INS than there is between HIPR and a million other action games. I don't even mean 'tactical realism' type games, either. As a developer, I think you're competing for people's free time. People play games in their free time because they're fun. Because of that, you're really competing against any other game that's fun, since I don't think many gamers play INS/HIPR/Rainbow Six/Battlefield 2/etc to the exclusion of other games (Quake, Warcraft, etc). Thematically speaking, INS and HIPR are similar. Beyond that, the similarities apply to a zillion other games as well.
HIPR is never going to be a game that will have a thousand people playing at once. I have no illusions about that. I've had the opportunity to work with some very intelligent, fun, and committed developers on this project, and I've made a number of real life friends as a result. I've stuck with it because we have a tight (and very old) community and we have a good atmosphere. I take the work seriously, but not too seriously. If it can't be fun and educational, it isn't worth my time. So I try to keep it as such.