Quantum Slipstream

First off distance within the slipstream bears no relation with the distance in realspace, rather the distance is tied to the skill of the pilot and the regularity of passage by ships (regularly used routs are shorter than little used ones). This means that travel between two major worlds in different galaxies(For example, Tarn Vedra in Andromeda and Earth in the Milky Way) would be faster than a trip between two minor worlds that are in the same galaxy.

Another important point is that navigation MUST be done by a biological intelligence. The official explanation seems to indicate it is a combination of both pilots tending to make the correct choice, and the choice tending to make the path correct.

Like Star Trek's Warp Drive, Slipstream has the capacity for time travel under unusual circumstances (use of a purple pilot with unusual procognative abilities)

I think Quantum Slipstream in Star Trek is more like a path than a tunnel (e.g. Transwarp). That is, you ride on it rather then through it.

Doesn't make any sense to me but hey, it's Voyager.

Another way I've heard it:

Quantum Slipstream is an area in subspace that is already moving at warp speeds, when you jump on to the area you're automatically at a high warp velocity, and then you can add to it your ships normal high warp velocity so 9 + 9 = 3032 times the speed of light.

I believe Slipstream is faster then Transwarp.