"The overall speed of Netbeans (even though it's a Java applicatoin) is much better than Aptana, which supprised us. "

Huh? You do realize that Aptana is a Java application as well, don't you? In fact, Aptana is simply a forked Eclipse. They re-sync with Eclipse base every once in a while. The only Cocoa IDE is XCode. Komodo is written as a Mozilla-based application. But, every other IDE out there (that I know of) are all written in Java.

"You do realize that Aptana is a Java application as well, don't you?"

Yes, I am fully aware of that (hard to miss when looking at the time it takes to start :)).

I don't really mind the loading time though; As long as the IDE is stable, I'll only start it once a day and use it throughout that day.

I'm also familiar with the Aptana/Eclipse relation. After using Eclipse-PHP/PDT for some time, my company decided to switch to Aptana because it was just a bit more 'polished' than Eclipse. Eclipse as a platform is very powerfull but, like many open-source packages, it just misses some attention to detail that Aptana (by a small margin) does.

Regarding the speed/performance of Netbeans; In the first few hours of using Netbeans, it became obvious that Netbeans cleverly uses different threads/processes for different parts of the application. For example: try to start a block-comment in a large CSS in Aptane ('/*'). This will completely 'freeze' the editor because Aptana starts rebuilding the 'outline view' (the tree-structure of the CSS file). During that time, it's impossible to continue editing the CSS file.

Netbeans on the other hand keeps the editor 'responsive' all the time. Not only is rebuilding the outline faster, it is also done in a separate process/thread. Doing the same in Netbeans causes the outline to show a 'spinner' while it's refreshing. That's fine with me as I don't need the outline-view when I'm typing inside the editor.

Another test was loading a 3MB XML-file. Simply loading the file in Aptana took several seconds, in Netbeans it was almost instantly.

Downsides of Netbeans? Yup they're there. First of all, Netbeans does not show a list of all your projects in the 'workspace'. I have become to like that feature very much over the last few years. It allows me to quickly 'switch' to another project if a customer calls for some urgent modifications in his project. I'll probably will need to get used to that.

Another feature Netbeans currently doesn't offer is showing 'inherited' properties/methods of PHP classes in the outline-view. Our code uses a lot of 'extended' classes, which Aptana neatly shows in the outline-view. The outline shows all methods of the current class, it's parent hierarchically, which gives me a nice overview in an instance. I'm really hoping this feature will be implemented soon as I'm not sure I'm happy without it :)

Thanks for the 'heads up'. Latest version now posted, 2.0.2.