I've been running Jaunty on a Gateway 503GR. This is an older PC with a 3GHz Pentium IV CPU, 2GB of RAM, an ATI Radeon 250 graphics card, and a 300GB SATA (Serial Advanced Technology Attachment) hard drive. Even on this 2006 vintage system, Ubuntu ran quite well.
Specifically, here's what I've found, so far, in the new Ubuntu (http://www.ubuntu.com) that I liked, and I think you'll like as well.
1) X.Org server 1.6/GNOME 2.26. The first part gives you peppier video performance, while the second gives you a really, nice integrated desktop. Particularly nice features include the integration of the Brasero CD/DVD burner with all other Gnome applications and improvements with both audio, PulseAudio, and multiple monitors control and support.
2) Evolution 2.26.1. Someday soon I need to a piece explaining, in detail, why Evolution is my favorite e-mail and groupware client. For now, though, let me just mention for the Windows users out there that Evolution can now directly import Outlook PST (Personal Folders) files directly to Evolution. With this, you can bring your e-mail, contacts, appointments, tasks, everything from Outlook to Evolution. It also now has support for Microsoft Exchange's MAPI (Messaging Application Programming Interface) protocol, Outlook's native protocol.
In other words, Evolution is now a complete and total Linux replacement for Outlook. If the only reason you've stuck with Windows is because of Outlook, you don't have to stick with it anymore.
3) Fast Booting. Are you impatient? Do you want your computer to work when you're ready to work? While Ubuntu 9.04's no instant-on operating system, like the embedded Linux SplashTop, it is mighty darn fast.
How fast? Well, I didn't see a boot time of 17.5 seconds like some people have, but I was up and working in 41-seconds, which for a box from 2006 and a conventional hard drive is pretty darn impressive.
4) Ext4 file-system support. After a while, I decided to try the new Ext4 file system option on my box. By default, Ubuntu still uses Ext3. But, after playing with Ext4, I may start switching all my Linux desktops to Ext4.
I'd make this change because Ext4 is simply faster than Ext3 without the stability problems I've ran into from time to time with ReiserFS. That boot time of mine, for example, improved by a second and a half when I started using Ext4. I also found that file-writes, in particular, went a lot faster.
5) Linux kernel 2.6.28-11.37. I'm not going to get into the technical details here, but the Readers' Digest version is that the latest Linux kernel has improved disk performance; better SSD (solid-state drive) support; and superior virtual memory scalability. What all this means for the likes of you and me is that you get noticeably quicker performance from your storage drives.
Overall, I'm sold on this new Ubuntu. Good solid features and better performance makes for a winning package. Try it yourself. I think you'll agree.