I am not an expert but I've always had 'buggy' sound experience in any virtual machine regardless of virtualization software (i.e, virtualbox, parallels). I find it interesting that you couldn't even open an audio file in Parallels. I just had the exact same problem but I was using Virtualbox. I think the hardware support for XP might be finally beginning to to slip a bit.
As to your query on 'what are advantages to using Parallels over others,' I've pondered this one a lot. One thing that Parallels does much better than Virtualbox is periphery support like printers and usb devices. You really have to have a strong working knowledge of linux (if your host os is linux) if you want to set up and use shared folders between host and guest, or the host's printer directly. It is much easier in Parallels (IMHO).
Another advantage I've found with Parallels is cloning, backing up, transferring between machines. Parallels includes all the transfer software and tools. In Virtualbox I could never really figure out how to clone and transfer.
If you have no need to move your os to another machine, and no need to clone, and no need to print directly, then I would say there is no benefit whatsoever. Likewise, if you don't mind reinstalling from scratch every virtual mahine then Parallels would have no benefit for you.
Keep in mind, Virtualbox has some big advantages over Parallels. The biggest one is the "seamless mode" in Virtualbox. I think Parallels have a "coherence" feature but it is not available in the linux distro I use as my host. Also, virtualbox works on any distro and any os, whereas Parallels is limited, and shamelessly behind in many cases. Even today, Parallels doesn't officially support Ubuntu 12.04 either as guest or host.
Last edited: Aug 17, 2012