This actually looks like it will be solved pretty soon; Microsoft VR headsets have been using inside-out tracking for a year and a half, the Quest will use it,

This actually looks like it will be solved pretty soon; Microsoft VR headsets have been using inside-out tracking for a year and a half, the Quest will use it, and a revision to the rift is widely expected to launch soon with inside-out tracking too. SteamVR tracking might have some advantages if you want lots of tracked objects (that may be outside the headset's field of view) but it seems like good-enough inside out tracking will be widely available this year.