Maybe it the solution to your problem does not involve the saddle as much as your cycling posture.The width and weight of the saddle may be irrelevant in your case except for self image.
I'd still recommend that you reconsider riding in the drops, unless the "efficiency" is so important that it over rides the associated pain and discomfort for you.
Well, I actually changed out my stem from a 6 degree to a 40 degree stem. So my posture is pretty darn upright for a road bike. I typically use the hoods, but since losing some weight having gone to riding in the drops sometimes. It is mostly for a change in hand position or for fighting a headwind which is common around here, especially in winter time. I also use aerobars for the same reason. I gain a good 2-3 mph on the aerobars.
Since the saddle has gotten to be much softer with the breaking in period it is bothering me less and less. I mostly noticed the problem when I only had the saddle for two weeks before embarking on a 159 mile ride over two days! Mostly I was just curious to see if anyone else had done it and what the results were. There is no way I will chop it without seeing other success stories.