Most of those systems result in many people geting sick because of latency and lack of precision of the headtracking systems.
Thats why the castAR system is not exactly a HMD, but an augmented reality system, but nevertheless suitable for applications as described above.
HMDs without headtracking system made it on the market:
- The ZEISS cinemizer
http://www.zeiss.com/cinemizer-oled/en_de/home.html
- and another one by Sony.
We used the Zeiss cinemizer and combined it with an external headtracking system in the company to build a demonstrator for a system without the budget to use original components (military aircraft HMD were out of budget and their use and distribution is limited by several regulations).
However, the headtracker that was good enough to avoid people from getting seasick exceeded the price of the HMD.
The Oculus Rift was not really ready for serious use at that time (and still is as far as I know).