<p>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.</p>

<p>What's the basic/big difference that I'll notice if I shift to Netbeans from Eclipse now?</p>

I think it will be mostly culture shock. Things in different places. Features named different things.
If you really want to give Netbeans a try force yourself to use it for a month. It will suck for the first day or so as none of the shortcuts will be the same, various idioms will be different etc.
At the end of the month you will be competent enough in it that these things should have gone away and you can objectively decide if you like it more. (I'm currently trying this with IntelliJ btw. Current state, confused ;-)