So for the sake of argument, let's specify that rather than using the Enterprise J or the Death Star....we use this:

VS

When it comes to size....the argument is meaningless. I'll show a chart

What will be important to prove, is weapon-strength, shielding, armor, various technology and speed.
Big D made a great point, that in order for the Enterprise to battle a Star Destroyer it would have to come
out of Warp Speed to fire ordinance. This is probably true, so i'll concede to that.
Also...when i said that Warp Speed is faster than FTL, my point was that Warp Speed is traveling
FAR faster than the speed of light. So if a Star Destroyer could in fact be proven to travel at FTL
at base, it still wouldn't compare to the Speed of a Warp Drive.
....she also made the point that the Sensors they have in Star Trek ROFLSTOMP anything Star Wars has.....so there's that.
Oliver Blackwood also said that Hyperspeed is faster than Warp Drive, and I already agreed to that
But I still maintain in my argument that the Enterprise can travel at far greater combat speed
than a Star Destroyer.
While a Star Destroyer travels at a slow impulse level, the Enterprise, when fighting outside of
Warp Speed has been shown, along with other Federation Vessels to be able to maneuver with
great ability compared to what we have seen with the Star Destroyers.
I think the speed disadvantage for Star Destroyers is clearly shown in this video. Where Star Destroyers
and CIS Frigates are at quite close quarters when fighting, and don't even attempt to move at quicker
speeds in order to manuvear against each other.
In this video you can see that the Fighters do most of the quick attacks. The Rebel Cruisers and Imperial Star Destroyers
once again are slow as snails. This can be especially seen when Admiral Ackbar orders evasive manuvears and they only
move to the left a little bit.
The reason the fast-action focuses on the fighters, is because the Cruisers are dead weight when it comes to speed.
I think the speed superiority Star Trek ships have is quite obvious compared to Star Wars Battleships
This video from First Contact(skip to 2:00) will also clearly show how large Flagships in the Federation have
superior manuvearability to anything Star Destroyers display