they could have just gone to plaid...
qs, could that be going over the infinite warp speed thing?
the infinite warp speed at warp 10 is an error, at that subspace layer, subspace just cant handle it, you get a high vibrational rate... which explains the mutations that occured in VOY
it's like takinging a rubber band, stretching it, and letting go
because of the instability of warp 10, this gives the appearence of infinite speed and in a way it is, and you you appear at every point imaginable on that path, but you're vibrating more so than physically moving which is why when they ended the experiment they where in the same place as when they hit the barrier and why they didn't die crashing into an object that will be there at some point along that infinite path...
thin is thats a problem cause the only velocity they know of for 10 is infinite and not the true speed based on the ability of the level of subspace.... thing is
because of this instability, warp 10 is two dangerous you die, or end up in the same place anyway

and if you live you mutate into a lizard

but since they say 10 = infinite, you have the energy and speed skyrocket between 9 and 10, cause it's not so gradual anymore...
if they stabalize subspace, and actually Transwarp is a generic term for beyond warp or beyond the limitations of warp, so if they make it stable , being able to manipulate the fabric of sub-space, a true value for warp 10 will be achieved and they'll have to redo the sacle
we know that warp 9.99 is well under that threshhold cause the fastest sarfleet ship goes at that speed right?
well because they never mentioned the amount of energy to reach 10, in VOY, and other sources, and in the chart its assumed to be infinite cause the speed is inifinite, which isn't the case because if it took infinite energy to reach 10, you'd never reach it no matter what, so reaching warp 10, the warp 10 isn't the same energy eise as the warp 10 on the chart, but without exact numbers you have to really ust assign something, so they said infinite, once a true value for 10 is found,
what why now consider warp 9.99999 or so may be 10, and if they mentioned the energy required to hit that layer as well, 9.999 or so could be just 9.9 or 9.8 or so on....
so the current chart is a little confusing so yeah, they will have to redo it eventually as its rather innefficient
but 10 is considered the Transwarp barrier because you can't get to it using a normal warp drive because not only do you have to reach that level, you have to stabilize it, something a warp drive cannot do, you need a separate sysytem, ex transwarp drive...
and since Transwarp is a generic term as stated aouve, QSd fits into it so yes, QSD is a type of Transwarp... lengthening the warp field forward through the deflecter into a tunnel, wormhole is what I like to call it.... lol
as for speeded it depends on how fast you can go throuh the tunnel (safely), the actual quantum structure of the tunnel ect.
so different QSD's different speeds because it's more about stability than simply speed now...