Cheap Price, Cheap performance
I researched a lot of home NAS devices, and eventually decieded based on price. This unit was the cheapest, and had the funtionality I needed.
However, performance was very poor, probalby due to the low power CPU the unit has.

A unit like this would be great for storing backups, etc (items you dont use very often), but for music/video/sentralized storage, I'd NOT recommend this produnt.

Just what our busy home network needed!
I read alot of pretty negative reviews of the NAS 200 but decided to buy it anyway. My experience with this product has been entirely positive. I owned the earlier 'SLUG' model from Linksys and the NAS 200 is a massive improvement.

Many of the reviews talk about how slow the NAS 200 is at uploading/downloading. Personally I just don't notice it as a problem. In fact it seems pretty fast to me. My primary interest was to install a RAID 1 backup server with good FTP server access so I could easily get to my files while on the road. I dropped two 500 GB SATA drives into the unit and configured RAID 1 giving me around 450GB of storage with the comfort that if either drive fails, I can replace it and not lose any data.

The FTP server function seems to work well. I configured all the computers in the house to be able to easily connect to the NAS 200 through Windows Explorer and I setup the free (1 year) Dynamic DNS service so I can navigate to the NAS 200 from anywhere I can get internet access.

Note that getting access to the NAS from the internet will require you to configure internal "Port Forwarding" on your NAT home router. I think the unit comes with instructions for setting this up on the Linksys WRT54G. In any case, you will need to forward port 20 traffic. Make sure you understand how to setup 'strong' passwords or every nut on the the internet will gain access to your NAS 200!

Overall, I am very happy with this product. As some may have mentioned the cooling fans are a bit loud so you may want to find an out of the way corner where you have cat 5 internet cable access to your NAT where it can sit and "hum".

The one thing I felt this unit should have offered was a Print Server function on one of the two USB ports. It doesn't.

Bonus info 1: note that the NAS 200 does not support NTFS on the internal SATA drives. You can however add USB drives that are already formatted in NTFS and it will work fine.

Bonus info 2; you cannot control who gets access to the data on the USB drives. In effect when you add a USB drive it becomes 'Public' for all registered users to read/write.

Good buy - I would recommend!
I purchased this device to use the SATA hard drives from PC that I recently replaced. It works good, easy to install the hard drives, easy to setup as network drive on multiple PCs.

I now have a backup copy of all critical items from multiple PCs on the NAT device.

Cons:
Must format SATA drives, so any old data on hard drive is lost.

I can not get the device to be accessible from the internet. Maybe related to my Hughesnet service. I need to contact linksys for assistance.

Speed is limited by network connection speed. So seems slow compared to internal hard drive speed.

Plain and simply, it works great!
After inserting a 1TB Hitachi HD and installing the driver from the CD that came with it, I was up and running in 15 minutes flat. It works great, as described by the manufacturer. I own several other Linksys products and their consistant high quality and excellent Customer Service are just number one in my book. Basically, if I'm looking for any computer peripheral and Linksys makes it, I look no more.

Works with Linux (and Windows of course)
The Linksys NAS 200 does not come with NFS type file sharing support, a critical service for die hard Linux folks. The NAS 200 does however, have FTP services and CIFS services. Not a deal breaker at all.

The easy fix is to install SMBFS for your Linux distribution! For Debian folk its as easy as "sudo apt-get install smbfs"

Then follow the example shown for the mount command like so

"sudo mount -t cifs //nas200ipaddress/PUBLIC\ DISK /mnt/nas -o username=you"

(The old school smbmount mount type is buggy and was replaced by cifs over a year ago)

Linux folks could also use curlftpfs for ftp mounts. The performance I experienced was buggy with large file transfers causing me to have to drop back to a standard ftp client for large files and bulk transfers. The cifs mount worked fine in all cases.

I took advantage of free shipping with Amazon and also purchased two 160GB SATA drives for quick and easy installation. The web interface for the NAS 200 guided me through configuring these two dives as a RAID1 mirror with no trouble at all.

The NAS 200 also has a built in http service used for configuration of the device. Not documented well is that any web browser client may be used to also view the files stored on the device. This is a great feature! My son loves to look at all the digital pictures we have saved over the years and now can do so without the possibility of accidental deletion. The http service also worked great streaming video to VLC across our home's wifi network.

Just remember that any files you copy to the PUBLIC DISK share is read/write access for all defined users on the NAS 200. Your personal stuff should, of course, be saved in a share defined for your desired username. Just read the product manual for more info.

So... the NAS 200 was purchased with the intention of replaceing a very old Linux PC acting as our home's file storage server. The NAS 200 works great with our Linux and Windows PCs, file transfers seem snappy and are error free, video streams from the web interface without lost frames. Thanks Linksys!