I recently got a Dell XPS 64-bit Vista for myself. Eclipse doesn't have their 64-bit version, but I've read on forums that they download Eclipse and work with Java 1.5 on the Vista with only some problems. I have Java 1.6 and Netbeans was easily downloadable.
What's the basic/big difference that I'll notice if I shift to Netbeans from Eclipse now?
What is the difference between Coke and Pepsi?
Ok, it's not really that similar, but a lot of the differences are in qualitative ways. Speaking of Netbeans 6.1 and 6.5:
Netbeans has a very different UI and workflow. There are no perspectives, but toolbars and such will auto appear/hide as needed (i.e. debugging). Build process is different. Managing projects is different.
Netbeans focuses on a smooth, integrated experience sometimes at the expense of features. The Profiler is fully integrated into the editor (context menu's let you quickly manipulate the profiler), but is lacking some featuers of Eclipse profilers.
Netbeans has a tightly integrated JSP/Servlet/JSF development environment. The whole workflow connects together from development, debugging, deployment. This is more of a "feel" than anything else.
Netbeans editor is missing several Eclipse features. Spell check being one prominent one. Quick complete (Ctrl-K, Ctrl-J) is an underused Netbeans feature. Snippets being another (though they have an auto-complete template which fills a different, but similar niche).
Less choice. If you don't like one of the included tools, it's unlikely you will find a good alternative plug-in.
Matisse. Eclipse GUI editors have started to catch up, but they are simply no comparison to Matisse. Superficially, they seem equivalent...
<sarcasm>
Your friends will make fun of you.</sarcasm>
The build system is different. Eclipse has an internal build mechanism whilst NetBeans relies on ant.
The popular Mylyn productivity tool is a key feature that is only available in Eclipse.
A Joel on Software forum participant wrote: "I've been drawn to Eclipse by a few features, notably: Mylyn, and would like to try it out." http://discuss.joelonsoftware.com/default.asp?joel.3.703449
Mylyn provides integrated access to your bug and issue tracker. When you work on a bug or issue, Mylyn focuses the Eclipse UI on only the code that is relevant for the task at hand.
Maybe when you work with several (many) projects at the same time I would prefer Eclipse (Workspace organization is great for that). Interface seems to respond better (at least vs old versions of NetBeans such as 5.0) in Eclipse too. This is related to SWT vs Swing performance issues, though the differences are no so big as on Java 1.4 days.
However I would say Netbeans is a better integrated IDE, you launch/debug applications the same way no matter you are developing a desktop application or a JSP/Servlet web application. Building relies entirely (since version 4 I think) on Ant, and Netbeans launches/adds ant target transparently. Ant in Eclipse has the same level of integration as a pair of bull horns sticked to the front of your car.
Eclipse is more extensible than Netbeans but the last is more uniform.
The basic workflow of Netbeans is much smoother and more reliable; little things like ^X to cut current line work properly. It's also simple enough to understand what it's doing.
otoh, Eclipse has the emacs quality of being a platform in its own right; some people swear by that.
Edit: I've changed my mind, on coming across HyperAssist: https://bugs.eclipse.org/bugs/show_bug.cgi?id=159157
Quite simply, the HyperAssist plugin fills in the missing piece that kept Eclipse from the gold medal; with it, Eclipse is the best IDE I've ever used.
I've been recently trying Netbeans 6.5 and have found/understand:
Multiple classpaths - you have compile time, run time, test compile time and test run-time. This means if you add something as a test dependency (that your build script knows about), it will not be visible to the main code. Again, very good for IDE / build server consistency.
Marker navigation is through the task list rather than through the current file.