I can see that, it certainly has a javelin sort of feel to it. Though would being extra long an thin actually help navigating that sort of thing, if you bumped slightly up/down/sideways you could tip the other end of the ship into the side of the vortex. I’m thinking back and seeing Borg spheres operating quite comfortably in transwarp conduits, or Xindi superweapons in …the thingies the Xindi used…
Well, those are different kinds of conduits. Like I said, my theory is that slipstream conduits are hard to stabilize, and the bigger they are, the harder it gets, so you want your ship to be narrow. It's not about the relative dimensions of the ship, but the absolute maximum practical size of the conduit. If you can't practically make a stable conduit wider than, say, 200 meters, then you need to keep your ship narrower than, say, 150 meters, and so the only way to have a bigger ship within that constraint is to make it longer.
By analogy, in the
Stargate franchise, the maximum diameter of a ship that can pass through a Stargate is the inner diameter of the Stargate itself. So if you want to make the ship bigger, the only option you have is to make it longer.
Actually the main reason I came up with this idea is as a possible explanation for why
Titan hasn't been given a slipstream upgrade. Maybe it's just too wide. Maybe such an upgrade will have to wait until Starfleet devises a way of stabilizing a wider slipstream vortex. But again, that's only my personal hypothesis and I don't know if Margaret or other authors would choose to go along with it.
I get a bit of reverse pod racer feel from it though, the nacelles are so far back, or rather, it's so long an thin they appear far back. They look like they're being dragged along behind almost.
Well, nothing wrong with that. A train can drag hundreds of cars behind it; no reason a spacecraft couldn't do the same, at least if it weren't dependent on propulsive exhaust coming out the back.
And since a slipstream generator is basically a modified deflector dish, my guess is that those nacelles are for conventional warp drive to use for shorter trips. So while the ship is in slipstream, the warp nacelles might just be dead weight, in which case "dragged" might be an appropriate term.