Screen Sharing vs. Apple Remote Desktop

Controlling it from what? Another Mac OS X Leopard system? If that is the case, then it has been my experience that the build-in screen sharing client and server has given very good performance.

If you are using a 3rd party VNC client (or server) with either the built-in Screen Sharing server (or client), then I have found that the Mac OS X components do not play as nicely.

You might check out Vine Server (aka OSXvnc) as an alternative server and JollysFastVNC as an alternate client.

NOTE: Apple's Remote Desktop is still using VNC. It is designed for managing a class room full of Macs (or similar many to one situations). So the features in ARD have more to do with managing lots of Macs, not performing a 1-to-1 connection.

Well you can have Linux/Unix X-Windows displayed on the Mac, but the Mac does not use X-Windows as its GUI, so you can not use X11 to export your Mac windows to another platform.

You can use VNC.

The Vine Server (aka OSXvnc) allows reduced colors, and I find it works nicely across the internet (but your mileage may vary).
<http://www.versiontracker.com/dyn/moreinfo/macosx/16699>

And if you want to control a Windows system you can get Microsoft Remote Desktop Connection Mac OS X Client (free)
<http://www.microsoft.com/mac/products/remote-desktop/default.mspx

Microsoft provides instructions on the web page where you download the RDC client.

Or install a VNC server on Windows, and use JollysFastVNC, or Chicken of the VNC, or Mac OS X Screen Sharing client, or use the X11 based TightVNC client, etc...

Talking to a Linux/Unix system you can export X-Windows to Mac OS X (perferred method is via 'ssh -X' from Mac to Linux/Unix system and use the X11 tunnel created by ssh).

Or you can start a VNC server on the Linux/Unix system and use the same set of Mac OS X VNC clients mentioned for windows.

But when it comes to exporting the Mac OS X display, VNC is the current method, and there are several different VNC servers you can use: Mac OS X Screen Sharing server, free Vine Server, and I think you can buy a RealVNC server (not sure about that), and maybe someone else has a server.

And my choice is the Vine Server when using 3rd party VNC clients (eg any VNC client that is not Mac OS X Screen Sharing client).

Since this forum is user-to-user, you should give Apple Feedback at:
<http://www.apple.com/feedback/macosx.html>

And while you did mention exporting X11 windows on Linux/Unix systems, I must say, from years of experience, that X11 is not always better than VNC. The X11 protocol can be very "Chatty" and depending on how the application who's windows you are exporting is coded, it can be orders of magnitude slower than a VNC session.

At work, we frequently use VNC to access a remote Linux system instead of exporting the X-Window (where remote is 2,000 miles).

However, I will agree with you that Microsoft's RDC is Best-of-Breed when it comes to remote desktop access. Besides giving good screen performance, it also exports the audio, which can be nice. The only exception is that it does not allow more than one viewer. At work it is helpful if more than one person can view the screen of a remote systems when trouble shooting, and for that we resort to VNC.

Again, tell Apple what you need in screen sharing via the above Feedback link. This forum is good for finding out what other Mac users are using and finding out if their experiences match yours. It is not good for telling Apple what you would like to see.