That really hits it - power and speed don't necessarily mean comfort. Related - a position maximizing power and speed may be relatively comfortable at a fairly high power output, but not loafing along. And vice versa. Loafing on my fast bike isn't very much fun. Trying to push my slow bike fast doesn't do me very well, either!
And there's just different style choices that influence pedaling. If I set myself up on a tall long frame I start pedaling toe down, stretched out. If I set myself up on a shorter bike with more reasonable drop I end up with a neutral foot position. Just as comfortable. Drop into my old "touring" type position (short TT, bars level with saddle) my saddle ends up back a bit and I have a bit of heel down, fairly slow cadence. I haven't ridden either of the end members in forever and consider that middle "standard" position as normal. That seems where most of the fit systems seem to direct people.
http://www.prodigalchild.net/Bicycle6.htm#FrameChart seems to give almost as good a result as anything else for "normal" geometry bikes. I fit almost like this chart for a 73 x 73 bike. I ride a 73.5S x 72.5H these days, so the TT is a little shorter, same fit. Then add the drop
http://davesbikeblog.blogspot.com/20...ebar-drop.html which is dead on for what I ride. Makes me look like I really fit on my bike. No surprise.
Moulton also points out that for touring or comfort, go up to 2 cm larger. Sounds like Rivendell fitting. I'd have a 58.5 with Riv fitting. Gives me NO crotch clearance and a 58 cm TT. I'd be quite stretched out even with very high bars. Weird. But add 2 cm to my usual per Moulton suggestions and I end up with a 56 or 57 x 56.5, which is what I used to ride touring with a load.
Funny how experience gives a basic good fit for almost everyone without fancy $$$. And the fancy fits don't give the ultimate fine fitting details anyway. Exact reach, exact handlebar tilt, etc. When I get my saddle right I can learn against a wall and reach forward to grab my front quick release.
The performance positions can be very comfortable but don't seem to offer much room for misadjustment, and certainly are unlikely to be comfortable for loafing. The really high performance positions for really reaching out ahead of everyone start to get into compromises in comfort. I see this reflected in the peloton. The big boys have the super fancy racing positions giving solo speed. The domestiques seem to pop up on traditional mellower stage race bikes. The Specialized Roubaix seems to show up for example. Fast enough, but just enough mellower in geometry and positioning to be distinctly comfortable when set up appropriately. Colnagos tend to be that way too, surprisingly comfortable when carefully fitted.