Personally, I dislike the official design that graces Titan novels. I expected something a lot more elegant, not something clunky and rather ugly.
I know there was a contest before that design was chosen.
The problem with Pocket Books' Titan design contest was how the ship was described. It was pretty much the exact opposite of the impression I got from Nemesis.
Riker's ship is called the Titan. This is obviously a reference to the powerful Greek gods, since it was established that Riker was holding out for command of the biggest, bestest, baddest ship in the fleet (which was the Enterprise, but he couldn't have that), so "Titan" is more of a meme for his ship being all of the above. But instead, PB decides that the ship is small, and "Titan" is just one of Saturn's moons like the other ships of the class. It kind of completely deflates the original intention of the name.
It also didn't help that, while adhering to PB's rules, the finished product looks like a cross between an Akira and a Sovereign. It's very unoriginal (and that's not a knock on the designer, who I know is very talented).
Did maybe John Eaves do a concept sketch for Nemesis, if it was ever considered to show the ship?
The only "official" drawing was a joke concept art that someone did and signed Rick Sternbach's name to it (Sternbach told me he didn't draw it). It was captioned, "Riker's ship for new movie," or something.