I can't say I'm a fan of FJ's dreadnaught. And my impression of the Saladin Class is
this.
The dreadnaught is too much a kit-bash. Both the upper and lower saucer are exactly the same shape. Why again? Joseph was not limited to budget. He could design whatever he wanted. The front and back of the stardrive too -- identical deflector/communications dishes. The nacelle pylon leading to the third nacelle? Make it another neck dorsal; what the hell.
And where he did get creative, it wasn't very creative. The shape of the stardrive is a formless tube. The nacelle pylons are overly thick and stubby, undercutting the brilliance of the thin/sufficiently strong Constitution ones. The space above the front deflector? Derp...I dunno...stick a couple more mini deflectors on there; what the hell.
And, of course, they're all Constitution parts, copy and pasted and stretched where needed, but not distinct. We're used to kit-bashes today, but then? Again, with the unlimited budget of lines on paper?
Beyond the quirky idea of the third nacelle, there's little to really admire in it. Then when you consider the two-nacelle rule, it becomes even more just cut and paste-y silliness. I'm not a diehard for the rule, but I don't know that the design has earned its choice to break it. ...something that might have been interesting is if he had it so that the three nacelles were working in concert with each other. Maybe if the grills along the nacelles were all facing each other?
Also, as a lily-livered peacenik, I don't know that I buy the dreadnaught as a warship. I've got a dick; I don't need a mega-phasered dodeca-nacelled über-ship to sleep well at night. The idea was that the Enterprise itself can handle most anything that comes in its path, and it wasn't a warship alone either. If, for fun, we're going to imagine bigger ships than it, I don't see why they then also need to be warships alone.