What I'm saying is simply this.
Jailbreaking introduces a slight lag. Then things you add ontop of that introduce more lag (like mobileSubstrate stuff and WinterBoard especially). So since it lags right off the bat, I don't feel good about even jailbreaking because then, I'll obsess over the lag and I WILL be looking for it. Staying stock gives me piece of mind that everything is running as intended to the best that it can run with what Apple has given us. I'm not saying stock is without bugs, but jailbreak and introduce non-Apple bugs? No thank you. I'd like to keep my iPhone as clean as possible for right now.
So Apple-bugs are ok? And FWIW, i bet if you go in there and manually delete half of what Apple gave you it would run even FASTER! No offense, but it definitely sounds like fanboy mentality that you're giving off here...Apple didn't even have time to get it right until 2.2 came out. And the attitude that "if you have less crap on it, the faster it's going to be" obviously goes for a lot of things in life, but isn't an option for those who want that functionality.
I appreciate that you're trying to stay true to how the iPhone was crafted, but blindly following Apple and believing that what they do is Gospel is pretty ridiculous IMHO. Sorry to say, but Apple doesn't always have the best interests of its iPhone customers at heart, and they've proven that with how restrictive they've been, ever since the 1st gen iPhone. Many jailbroken programmers have implemented functionality that Apple has for one reason or another refused to implement, not because it can't be done, but because either a) they flat out don't want to or b) they're trying to milk the thing as much as they can. Just wait for the iPhone 4G, it will allow you guys to FINALLY take video...what a breakthrough!
Last thing i'll say is, if Apple can implement most of the functionality that jailbreaking has given me, like tethering, theming, voice navigation, root access, bluetooth file transfer, copy and paste, etc. and do this WITHOUT any added lag to the stock phone (keeping in mind that Apple-induced bugs/lag doesn't get any more of a free pass than jailbroken-induced bugs/lag) then I will solemnly swear that I will stick with only what Apple gave me for the rest of my iPhone's natural life. Everything is a give and take...what you're essentially saying is, if you go buy a car, the base model should include everything in it already from the dealer and you shouldn't have to pay for aftermarket parts because they cost more or might increase the necessary maintenance on the car...that's just how it works. The iPhone has an OS of its own, and thus is like every other computer. If you use the computer with only the bare OS minimums, it's going to fly...later down the road as you install more programs, etc., it's eventually going to bog down. The thing here to understand is that the lag will be there...even if Apple implements it. It's not just going to go away, because most of what's causing this "lag" is a hardware limitation, not because of poor programming. And so the question here is, how much time is all of the added functionality worth? I really doubt that stock iPhones will EVER get all of the functionalities of a jailbroken phone MINUS all the lag...I just do not see it happening. But if it does, i will be more than happy to concede and say that Apple is supreme all along...