There's a certain disjunction between the desire to have a 'realistic' campaign world and the desire for continuing characters. When one reaches levels 9 and greater, there is a substantial amount of time invested in the character and campaign (even with 3E's more rapid rate of advancement).
Even in original D&D (as played by Gary Gygax and his friends), resurrection was by no means unknown. As he said recently, "I never lost any of my main PCs, although most of them 'died' at least once and were resurrected or wished back to life by their fellow adventurers." (
see here)
Conversely, AD&D had the limit on number of resurrections allowed, in two manners: the System Shock roll, and the initial Constitution limit. Of course, it should also be noted that these rules were being developed in an environment of extremely frequent play. For many of us, playing once a week is impossible!
I tend to think of 3E D&D (as it is presented in the core books) as being a lot like Dragarea from Steven Brust's Vlad Taltos books. (
Jhereg, Yendi, et al). High stakes, possibility of death, but there's enough magic around to overcome things if needed.
I think it's still true that permanent death is a real possibility at the lower levels of experience. Once play reaches 8th+ level, then
raise dead and similar spells become available. After that, the course of the campaign becomes more and more dependent on the DM. In AD&D, characters would retire at 12th level; such is no longer always the case - although I'm sure it happens for many groups because the DM is not happy in running campaigns at the higher levels of experience.
Where 3E really succeeds is in giving the power to groups to make the game their own. There is a huge amount of tinkering that everyone does with the game that makes each campaign very distinct. The prestige classes and feats a campaign makes available are the most obvious points of difference, but the rate of advancement and magic proliferation also vary from game to game, although low-magic isn't quite as easy in 3E without disturbing the balance between the classes.
Of course, it comes at a price: a game where the wealth of options can overwhelm people. I still like AD&D for its simpler structure. Although there are rules that I find nonsensical (the overly complex initiative system for one!), and lesser goals of the game - "we don't do everything, we just do one thing well" - make it still an exceptional RPG.
There is a certain world implied by the AD&D world, and another world implied by the 3E world, both of which have many things in common. One thing that is layered on top of that is the actualisation of those worlds as shown in adventure modules. The GDQ series, the S series, T1-4 and A1-4 define to a large extent what AD&D is about. Personally, I think most of the other AD&D modules diverge from that vision.
Because those module came at the start of things, when they were pretty much the
only adventures that could be found, there's much more of a shared conception of what AD&D was (and is, if you still play it!)
3E lacks that shared vision. Unfortunately, there aren't official adventures that have the same universal appeal (although I think the
Sunless Citadel comes closest). Even though Necromancer Games and other d20 System publishers may be publishing excellent adventures, they aren't as universally known as the original AD&D adventures.
That, then, is what I most miss about 1E: the shared experience given by those original adventures.
Cheers!