I have been spending some time the start of this term at University touching up on some Java. This year is my final year (3rd Year) and the only time we have previously covered Java was in the first year for about 12 weeks, in a somewhat basic fashion (Command Line eventually onto some GUI using JOptionPane) - At this time I had very little understanding of OO (Object Orientated) programming, just that we all knew we had to use it.
Last spring & summer I was teaching as a local collage (Barnfield Collage in Luton) where I saw a lot of students work in Java to a very high level - this got me back into covering some Java over the summer, at this point I understood OO a lot better from using PHP to a very high level, and this made Java seem like a lot better concept than it had in the first year of Uni.
I still find Java somewhat limited compared with C# and C++, and the fact that it runs on a “Virtual Machine” (in the loosest way possible) doesn’t help the footprint of the software developed.
However when it comes to Compatibility it wins over the C# that I love so much - recently I purchased a Macbook for the web development I spend the most time doing, and although I have Visual Studio 2010 running on Parallels Desktop it uses a huge amount of resourses.
Eclipse & Java (along with NetBeans & BlueJ) all seem to run so well! I have also found that you can have a MySQL server running with very low resources all the time, and the list continues. Going back 6 months my netbook with XP would bog down with the list of services I have running now - as well as a Virus Scanner (I use Kaspersky on Windows, although its a low resource virus scanner, it doesn’t comare to ClamAV!)
So my judgement is, Mac for developement (especially Java) is brilliant!