Workbench height is one of those subjects which is often discussed by not very well explained, in my opinion anyway. The most common expert advice you see is that your bench should be low, around palm height. I followed that advice, my bench was too low and I ended up building plinths to raise it up 4". Even now, it is sometimes too low and I use a "bench raiser" that is 7" high, making the top almost a foot higher than my bench was originally.
The best discussion of workbench height that I have heard is this one by Shannon at The Renaissance Woodworker. Begin listening at 8:30. He correctly responds to the question of how high your workbench should be with the answer, "it depends." He refers to his main workbench as a dedicated planing bench which is at palm height, for him 33". He has a separate joinery bench at elbow height, 45" for him. For some joinery, like chopping mortises, he uses his main bench, or even a sawbench.
I think he's right and, while the specifics of my three choices are somewhat different, I have ended up in the same place. Of course, there are craftsman who do just fine working at one height and that's just fine too. They have found a workable compromise that suits them. My experience is that a low bench optimized for planing isn't great for other tasks.
There is a great deal of room for personal variation. My workbench up on plinths is 38", 4" above my palm height. I feel very comfortable planing at this height, but I am fairly strong and probably rely on my upper body more than most. Part of the issue for me is that my arms are very long, making palm height relatively low. I can readily believe that if I used wooden planes I would want it considerably lower than 38" though.
My bottom line is that workbench height is a matter of your body, your personal preferences, what tasks you are designing it for and probably other factors as well. In addition, I think that you should make provision for working at a variety of heights if you can. If you don't have room for a separate joinery bench like Shannon has, there are still good options like bench raisers.
Shannon's discussion of workholding is good too. As time has passed, he uses his end vise less and less, to the point that he says he wouldn't even have one if he were building his bench today, and relies on stops more and more. This was the traditional way and I agree with his reasoning as to why it is better. I have found the same thing. When I built my Nicholson bench, I started off without any vise at all, but I did eventually end up putting a Veritas twin screw vise on the end, though I still rely primarily on stops and bench hooks. I have seriously considered taking the vise off and using it for a Moxon vise on steroids that would live on the end of my eight foot long bench most of the time.
Why are stops preferable to using a vise? It is a lot more convenient to work on a piece without having to clamp and unclamp it, the piece doesn't slip, it rests solidly on the bench and it's faster, especially if you have multiple pieces to work on. Here is a nice description by Mike Pekovich of the stops he uses.
There are obviously other good approaches. Paul Sellers uses his vise for most of his work and gets great results. I just think the older, more traditional ways of workholding are better.