Captain Jonathon Archer of the Pre Federation starship Enterprise NX-01 was introduced to the USS Enterprise NCC-1701-J when the mysterious starfleet time traveler 'Daniels' whisked him into the 26th Century to Azati Prime, more specifically the battle of Procyon V. The battle was against the invading force of the sphere-builders from another galaxy, who attempted to wipe out all life in the milky way - This is the only known encounter.
Very little is know about this ship however it still exhibits the design influences of its forerunners, it's much larger, sleeker vessel. It retained the elliptical forward hull of the 24th Century Enterprises but with the deflector array apparently mounted at the prow. The most noticable change is the exclusion of the traditional engineering hull and is instead replaced with a much narrower hull that emerges from the rear with the massive warp nacelles were mounted above on elegant upward curving pylons.
Upon closer inspection of what very little information we have of the ship, it can be extrapulated that this starship is at least one and a half times the size of the U.S.S. Enterprise-E and thus most likely is the home of many federation civilians, just like its predecessors
Daniels also informs Captain Archer that serving aboard the Enterprise-J are many former enemies of the Federation - Klingons, Romulans and Xindi.
While it can be considered to be significantly advanced than its predecessors, no other details of its specification are known.