I have been using the TNC-X since the early days and I love them. I love them enough that I have a Yahoo group set up for TNC-X users:
tnc-x : TNC-X Coastal Chipworks' KISS TNC We're about 400 members strong and still growing.
The TNC-X really is a great alternative to the commercial available, full blown TNCs made by Kantronics, PacComm, Timewave (fomerly AEA) and MFJ. However, keep in mind that the TNC-X is strictly a KISS TNC. This means the interface from the TNC to the computer speaks the KISS protocol and the software you are using must be KISS capable. This is usually not a problem for the average TNC-X user because they are usually running APRS, WinLink or both. Most APRS programs support KISS. Some good examples would be UI-View, APRS-IS and XASTIR (Linux variant).
The USB option on the TNC-X really is a dream come true. With the typical serial port going away on most new computers, especially laptops, we hams have to look for alternative connection methods. USB is the obvious next step, but simply using the USB protocol is not that easy since it requires drivers, ect. The TNC-X uses a unique (and very popular) USB to Serial IC made by FTDI. When the USB drivers are installed, the driver creates a virtual com port in the OS. This virtual port is now the port you would point your software at, to talk to the TNC-X and receive from it as well.
I actually used this same FTDI IC on a USB GPS module I created called the GPStick:
Not only can I now feed TTL serial data to a computer through the USB port, but the 5V bus voltage on the USB port will power the GPS. The same is true for the TNC-X, with the USB option. The single link will serve as the data link to and from the TNC-X AND power it at the same time.
You mentioned "You get what you pay for." Well that could not be more true with the TNC-X, you pay a fair price and get an awesome box for the money. Give it a try. I have eight of them and they all work like champs!
