The table of my 21" Pegas with the Pegas stand sits (when level) at full extention just about 37" off the floor. The leg extenders can be changed in two inch increments or about 6" total vertically. I currently have my front extenders down one hole (about 2"), so the front of the table is at 35" with the rear of the table angled up to around 38".
I puchased a workshop stool from HF that was much too tall so I had tho cut the legs down by 3", so my seat height is now 26". This combination is working for me, but still have not decided if it is optmal.
I am short and have short legs, so even with these dimensions, I had to make a support for my foot switch that raises it off the floor about 5".
If I have to satnd up to do any cutting these dimensions are OK as the vertical location of my head and hands are not that much higher then when sitting on the stool.
My bigest concern is seeing the blade/pattern line intersection comfortably. If I sit up straight it is hard to see. If I want to see the blade/pattern well, I find I'm hunching over. I also find my body position is effected differently when using spiral blades vs. regular straight cutting blades. When using Spirals I want to look down on the work while when using regular blades I can look at the blade/pattern more head on, if that makes any sence. So when using spirals I'm definately hunched over more and it is felt in my neck, shouldeers and lower back.
As for my arm position, I think my forearms/wrists are just about on the same plane as the table. Elbows extend out from my body and the table, but are not drooping down, unless I holding the work piece from below. This happens sometimes when the cut is near the edge of the piece and the piece extends out from the table significantly.
The table of my Porter Cable saw on its stand was just about at the same level as the Pegas. I have to beleive (I know giving more credit then may be due) that saw manufacturers who offer stands have chosens the stand hights to be suitable for most people.