I just purchased a Thecus n7700pro and am very happy with the hardware and frustrated by some of the absurd limitations and choices they've made concerning their implementation of Linux. Below is a post I made in another part of Hexus:

Well, first off: Thecus chose Linux as it's starting point, right? Then it's absurd to offer ZFS. Because of licensing issues ZFS cannot be incorporated into the Linux kernel and has to run via fuse in userspace - ouch. Because of this they aren't offering NFS with ZFS and I find that lame. Next, not offering ext4 is a bummer too. Only the most conservative of distros aren't using it yet like CentOS. There is an upgrade path from ext* to BTRFS which is already part of the kernel if you have one of the newer kernels. BTRFS will offer everything that ZFS has plus more and it's written in native Linux code - I can't wait. That being said, upgrading from ext3 to BTRFS will leave you with the performance of ext3 so upgrading from ext4 will be preferable. Myself, I will move all data and reformat to BTRFS and move everything back. I'm sure that'll be much safer. Anyway, that's possibly a long way down the road. In the mean time, here's what has me frustrated: not being able to create multiple partitions. I will be using my NAS to store movies and music, pictures, code and other small files. So I want to use 30% of my space using ext3 for smaller files and 70% of my space using XFS for movies and other large media since it's performance is much superior to anything else for that especially when using large (1024) stripes. Well, I can't do that with the Thecus. I guess I could install fsisk and do everythign from the command line, but I don't know if the changes will be reflected in the WebUI or if it will create warranty issues. So I've had to compromise and use XFS using smaller stripes to compensate for the smaller files. This isn't optimal nor is is a huge deal. It's just that I'm used to having such weird restraints imposed on me in a Linux system.

On another note, my experience with customer support has been great: they haven't always told me what I want to hear obviously, but they have been prompt and accurate and clear and have gotten back to me with in a few hours in response to every question or issue I may have.