@VariousNames
As stated from TWI, you can gain "Rank" by completing the Offline Training. And we don't know how exactly the Progression System works.
Even if we take the unlock System from BF:BC2 (i think TWI will easily surpass the "quality" of that System), you gain only minor Improvements as you progress through the Ranks. Within 10 to 20 hours of relaxed play your having more than half of everything avaible.
And even in BF:BC2 the last Weapons were seldom the "Best", its all about personal preference. A lot of players prefered the "noob" Assault Rifle, because the diferences between ARs was so minute.
So if BC2 got it right and not bothersome, do you really think TWI will do worse ? Really ? I don't think so, considering they have worked and probably tweaked on it for years now.
BC2 did not get it right for the following reason.
If the weapons are all equal, they should be available to all players at level 1. The grinding portion of acquiring them is totally unnecessary, limits player selection and variety. Only the players willing to buckle down and shoot the same 3 guns for, as you say....lol....10-20 "relaxed" hours (this is a lie BTW, at best a severe underestimate) have access to a bunch of samey assault rifles with remixed stat bars?
Of course, as an aside, there's the "perks" that Bad Company offered that new players did NOT have access to. Even Call of Duty managed to get that part right....if some players should have perks, all players should have them. It's virtually the equivalent of allowing some players to have rifles while others can't.
The solution is obvious, give me all the fun stuff and I'll decide which of it I want to use. The locking system is just a scheme to extort more playtime out of the user.