I was wondering what the benefits of actually using a 64bit OS are? If there a speed difference, is it just technical? Im not quite sure, because I have an AMD64 and have tried a few 64bit distros, and cant really see or feel a difference. Can someone explain this to me?

Lots of people claim there is no visible difference. That has certainly not been my observation, but I finally have a legitimate benchmark. I have an ATI AMD64 machine dual booting Debian i386 and Debian AMD64. Playing Gnometetris on both systems ... my scores on the 32-bit are 3 times higher than on the 64-bit.

There are other considerations in choosing which system to install, but a pure Debian 64-bit system is definitely faster than a 32-bit, all other things being equal.

I have tired both 32 and 64 bit without being able to notice anything for a webserver/sql/mail server

one of the disadvantages of 64 bit is that most apps are 32 bit. This makes your life harder because you have to do a bunch of chrooting inorder to install them. so you have to weigh the slight speed advantage with the installation difficulties

Ive actually been considering switching from a dual boot to strictly the 64 bit version of Debian. Its not so much certain app support Im worried about as using it for everyday things. Like will I have any trouble with Flash support or anything. Basically what Im worried about is losing basic functionality. So what do you think, should I just install Debian or just hold off for awhile?

If I could only run one distro on my AMD64, it would be the Debian AMD64 version. I ran it without the 32-bit version for quite a while, until I finally summoned up the will to delete Windows which gave me the space to run both. There is no question that AMD64 support lags behind the i386, but Debian, of course, is far ahead of other distros. There is no Macromedia Flash support for any 64 bit system yet, but Gnash is coming along nicely. Sun has, as yet, provided no plugin for browsers on 64-bit systems, but Konqueror doesn't need one. I run Gnome as my desktop, but installed Konqueror for that purpose. I don't really consider those things "basic functionality."

The biggest lack on is Open Office, but AbiWord and Gnumeric fill in nicely. Open Office on Debian has made it to an experimental stage, and will probably be available in Sid within the next few months. You can get the experimental packages here. I have been using them quite successfully, but they do sometimes crash.

The AMD64 installation is a bit tricky right now because of the move to Debian's regular repositories. I just reinstalled mine, tho (Etch/Sid combination), and managed to get a complete system. If you aren't willing to fight it a little bit, I'd hold off for a month or so.

I have been running Debian testing "etch" amd64 since last August. It has been quite stable, and fast, though I never ran 32-bit on this machine for comparison. As noted above, there is no Flash, or OpenOffice.org, but it has served well as a desktop system.

I think rickh understated the installation problems just a bit. This system has not been upgraded in months, and there is only a dim light at the end of the tunnel as far as I can see. Every time I look at an upgrade, whether with apt or aptitude, it wants to remove gnome, kde and x.org, among other things. This is indeed "because of the move to Debian's regular repositories", and the situation will not improve until that has been completed, which in true debian fashion will be "when it's time". Until then, the 64-bit testing release will remain messed up and unreliable as far as installation and upgrades are concerned.

As strange as it sounds, "unstable" is probably a better choice than "testing" for the near future, particularly if you are a debian novice.

It's been updated a lot. In fact, I just reinstalled mine from scratch just for practice, because I'm going to be setting it up for a friend in a couple weeks, and I wanted to make sure it worked. The base system installed without a hitch, but I had to wait about a day and a half for Gnome (Sid) to stop being broken. If you already have a Debian setup, and you want to get it straightened out, do it like this.

Use the Debian Etch netinstaller to get the base setup. During the partitioning phase, leave the /home directory alone, reformatting whatever other partitions you have set up. (You do have /home on a separate partition, I trust)

Don't install xorg or gnome. Change the sources list to 'unstable'. (I had to use vi proper for that, since vim is not in 'testing' yet for some reason.) From Sid, install vim, xorg, and gnome. (Also gdm if that's not included with gnome.) Since I have a new install I switched from apt to aptitude; not using the ncurses interface, just using aptitude instead of apt-get at the prompt.

When that's done, change your sources.list back to testing and wait for it to catch up. If you need anything else that's not on testing, of course, you'll have to go to Sid for it, but I wouldn't do a dist-upgrade from there.

Oops- I didn't mean the repositories, I meant my system hasn't seen an upgrade lately. I made the mistake of buying an ATI video card, so if x.org gets trashed, or if I upgrade the kernel, it usually takes a couple of hours of text mode downloading, head-scratching and swearing to get everything working again.

Here is the definitive resource for checking package status in debian testing: Why is package X not in testing yet?

Today I find that "1619 packages are trying to enter testing." I'll bet that several of those are ones that I need for a successful apt* upgrade, so it is no wonder that the package manager is confused. This is why I would recommend staying away from testing at this time.

Check the above link periodically, and use testing only after the number of packages "trying to enter testing" has dropped to a more reasonable figure. While you're there, don't forget to check the status of your special requirements, e.g. video drivers.