Okay, I'll toss in my zwei pfennig here.
First, I've got to agree with most folks, get Schwarz's book. It is illuminating to say the least, in large part because it really focuses on analysing what a workbench is designed to do, and how to evaluate whether a particular design or feature meets its functional goals. I've likely read most of the same workbench books you've read, and Schwarz's is IMHO the best of the lot as far as approaching the workbench as a tool goes.
I have a basic bench, built from a design in IIRC Sam Allen's book, with a second generation top. My first top was a 36" wide solid core door on a four foot long by 2' wide base. It had some real advantages, namely pretty much anything I wanted to assemble would fit on it, I had two sides I could work on when I wanted to, and I could easily stash my shop vac under the overhang. It also had some real drawbacks, mostly related to the base to top interface. I did not have a flush front, which started to haunt me when I began trying to do edge work. The back jaw of the vise did not set flush with the front edge of the top. The long overhang on the end ended up sagging, since the top was solid particle board core. The "apron" effect of having a 1.5" top sitting on a stretcher would cause me no end of grief when clamping things.
I tossed that top when I moved, and purchased a ready made solid maple top from Jorgensen when I got my shop out of storage. It is better, but I still have the "apron" effect. The vise is now mortised back.
What I've learned, having worked with two incarnations of my bench, as well as plenty of time with workmutts, is that Schwarz's book managed to distill my dissatisfaction with my bench, allowing me to critically analyze it and aim for improvements. I had been working on a new design, and have decided to make a few key changes. My new bench will have a thicker top so I can ditch the stretchers, 3"-4" thick. The only downside to the thicker top is I'll have to bulk up my arsenal of 12" Mini QuickGrips as the dozen 6" ones will be much more limited. It will be 7', maybe even 8' long, although I will go for 24"-30" wide. The width is because I don't put my bench against a wall, but much prefer to have access all around, and I work on all sides. No tool tray, because I have a bench brush hanging on a nail right behind me. I was planning on drawers, but now if I do have 'em, they will be a slip-in case, rather than integral to the structure. I will have a sliding jack or some such. I'm still undecided on the matter of vises, aside from the fact that I won't have a tail vise. Having finally broken down and purchased the Veritas Hold Down I can only say "man, was I an idjit for waiting so long on this one!"
The key thing though is now, I evaluate every design feature from the perspective of "how will this address some of the woodworking challenges I have faced and will likely face?"
I am a thoroughly hybrid NeanderNorm. I've cut mortises with routers, with hollow chisel attachments, with the drill press, with a handheld drill, and with chisels. I plane with both my lunchbox planer and with an assortment of handplanes. I've yet to cut any dovetails by hand, but do all sorts of other things, including airbrushing at my bench. My drill/driver is my friend, but so are my bench stops. I want a bench that is unmoving except when me and three or four Mr. Universe contenders persuade it otherwise, because I've had too many "bad things" happen when the workbench goes skittering out from under a workpiece.
Think through the work you'll be doing on the bench as best as you can, and the tools you'll be doing it with. Finally, remember that if Bench v 1.0 isn't exactly what you want, it can always serve as an assembly table after Bench v 2.0 comes along.