I always did like the Thufir and Andor classes with their protected nacelles. It's not a perfect piece of design (the nacelles are protected by the housing for their own PTCs, and I don't know how you'd jettison the nacelles without having them collide with the hull), but the idea is a good one.
One thing I never noticed in the FASA manual that I see now is that the connection between the Thufir's nacelle supports and the saucer is pretty slim--the cross-section fore to aft is smaller than the diameter of the bridge module! Would it be worth thickening that just a little so it doesn't look like the saucer is going to tilt forward and snap off in a gravity well like those on oh, so many Trek starship model kits?
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