After the patch that was deployed today (17.03.2016), I felt like Dreadnought had a bit more top-end power. So I did a comparison on the Transport track, to see if there's some improvement.
Dreadnought run only: https://www.youtube.com/watch?v=yN9xf-iRuMY
Dominator run only: https://www.youtube.com/watch?v=9bgytAjxH54
I want to point out the second open space, that nasty right corner. Dominator due to lightness jumps very easily there, much more than Dreadnought which results in a lot less speed since right now the game drastically reduces the speed whenever the contact with ground is lost. If it weren't for that, the difference would be about 0,5s, maybe less. And I'm not talking about bad landing/bounciness. Pure loss of speed when in mid-air.
In short, there's an improvement. Very good one to that, but still not close enough. I think Dreadnought should have a bit more top-end "oompf". Not earlier, just a few more unicorn farts when the VTEC kicks in xD And possibly top speed increased by 10km/h. That IMO would make it a lot better and give it an edge on the high speed sections.
To make it plain, Transport is a high speed track, therefore it's only natural that Dreadnought should've a lead of over 1s on a lap compared to other cars/classes. If you put it on Alhatra or Industrial, it will be slower than Dominator even with the buff I mentioned. I assume the issue with losing speed on jumps is temporary one and won't be present in the finalised version of the physics.