Herkimer Jitty wrote:
One doesn't necessarily have to follow the Star Trek Encyclopedia's take on transwarp. It is far more likely, IMO, that "transwarp" is a catch-all term for "faster than current warp capability" ("transwarp drive" never functions the same way every time we see it, anyways) and that Excelsior was succesful, necessitating the warp rescaling before TNG...
To be fair, we don't have to follow the Encyclopedia
's take that the warp scale was rescaled before TNG either. Onscreen, neither scale has ever been actually mentioned, much less actually followed (i.e., speed of plot being the general rule).
IMO, quantum slipstream is a form of transwarp drive, but a more specific one in the same sense warp drive is a specific type of FTL drive...