Yesterday I tried switching to the ParallelGC to see if it will improve my IDE's performance. I noticed that especially
when opening large projects, the task scanning can bring netbeans almost to a halt as the GC runs too many times.

After I made this switch netbeans had much less GC halts and generally seems much more responsive.

Maybe it should become a GUI option with the different GCs and an "Auto Detect" (which would be the default). Then the
auto detect should check how many cores/CPUs are available, and if more than one use the ParallelGC, otherwise the
SerialGC. 

I tried this one both my desktop+laptop, which both have dual core CPUs. Both have a noticeable difference and I'm able
to open large projects much quicker, and while it's scanning the project (even at IDE startup) I am able to continue
with my tasks. Some projects take about 15 minutes to finish scanning, and during this period I couldn't do anything.
Now I continue as if nothing is happening.

Further I also increased Xmx a bit on my desktop as I quickly reach the default of 512m. Maybe this should also become a
an option, as well as increasing the Xmx when Netbeans notices you reach the maximum often. For example, Netbeans would
have noticed that I get to 490mb/512mb many times and then increase it by 64mb, doing this with every start of Netbeans. 

These 2 together made my frustrations must less.