I have few problems with either, but I do most of my Maven work from the command line, regardless of which IDE I'm using. I still think IntelliJ is a better IDE, but Eclipse 3.5 brings them really close together, and Mylyn is a huge win for Eclipse until there's an IntelliJ version (and maybe there is now--I haven't been keeping track).
If you get a "cannot create the java virtual machine" message when you put the JDK path on the command line, you're not giving the correct path. The JDK path isn't the path to the JRE inside the JDK, it's the root of the entire JDK. Java knows how to find the JRE when it needs it.
For the most part, you can ignore Eclipse Maven whining about the JDK/JRE issue. It's only absolutely required in certain cases. The bigger issue for me is that I've yet to figure out how it's bypassing my targeting of a JDK and going to a completely different JRE. Since it's only one of my secondary development machines, I've never taken the time to resolve it.
An IDE is no substitute for an Intelligent Developer.
What OS are you running? Is the OS 64-bit or 32-bit? I ask because if you don't get everything correct, the JVM will not load. For example, using a 64-bit Windows OS with a 64-bit JDK and a 32-bit Eclipse will not work. I have had to install an additional 32-bit JDK on my systems just to run Eclipse. Fortunately, the next version of Eclipse will have a 64-bit version for Windows.