The sketch for the SM Flyer is a bit deceptive, because I suspect it was copied from a photo that was taken at an unfortunate angle (or possibly traced as suggested).
It isn't as "curved" like that, or as small as a land speeder.
Essentially it's a Storm Raven variant so is similar in aesthetic to that.
The only way I could describe it is if they cut out the middle of the Sorm Raven (the troop carrying bit), and then stuck it back together.
It does have different wings, but the engines are very similar to the Storm Raven's without the wing cowling, but gimble mounted.
The cock pit is essentially the same as the Storm Raven as far as I can tell.
Having said that, I hate the Storm Raven kit, but the Storm Talon is really cool. And it does look like vanilla marines will be getting one for def.
40k is a game where an appropriate response to "sir, a few dozen idiots in pickup trucks are approaching!" is "Bring out the irreplaceable thousand-year-old cyborg killing machine!"