I disagree with the 21st century VR system comment. The graphics and resolution have increased dramatically since the earlier versions. Some people like myself are simply looking for an immersive visual experience but on a decent budget. Tracked controllers and additional sensors become costly. Tracked controllers can become a hindrance in-game as well on a lot of platforms we're used to. Take for example an FPS - you have to spin around a lot to watch your back and spinning causes dizziness real quickly in VR. Then you're also talking about different gun types - pistols, rifles, etc. How would you hold them? Do you really want to purchase multiple devices to get that proper simulated feel?
@WifiBurger VR is the future . Aside from that joke, it truely is coming along especially if it was at a lower price. PS4 has VR, PCs, Xbone probably will have a version soon enough, and I know tons of people including my own grandparents and parents that find this interesting even though they have no idea what a "PC", "GPU", "CPU" or any other name for anything electronic is. My point, VR will grow, and exponentially.
"Of course, the device will have an IMU of some kind, but Lenovo wouldn’t even cop to its existence, let alone offer any details on it. (The only way it wouldn’t have one is if Lenovo used sensor fusion, which seems less than ideal on such a pricey item.) "
You have a fundamental misunderstanding on the purpose of Sensor Fusion. ALL current viable VR HMDs utilise Sensor Fusion between an IMU and a supplementary absolute positioning system (most use nIR optical, but there are RF and magnetic systems available). The LACK of Sensor Fusion would be an indication of a substandard system. This is because an IMU alone is not sufficient for accurate position tracking due to extreme drift from error accumulation (a limitation of Dead Reckoning navigation), and a commodity optical/RF/magnetic system alone is not sufficiently performant (low sample latency, high sample rate, high instantaneous sample precision).
Quite simply: Sensor Fusion is the method of combining data from multiple sources to produce one output. If you are not using Sensor Fusion, then you are not using multiple sensors. Multiple sensors are a fundamental necessity for VR tracking today, ergo any VR HMD will either be using Sensor Fusion, or be a failure.