Carbonfiberboy 

There's always lot of, I would hope, silliness about these discussions. What is carefully never mentioned is that the object of the "smooth pedaling" game is not to apply some even force on each pedal. Positive force on the upstroke and the lack thereof is a straw man, trotted out as though this were some important information. What's never mentioned is that the object is to apply as even a total torque on the bottom bracket as one can, while not overworking the more minor muscles. Looking at force on each pedal separately is silly. We use both pedals, all the time. OF course this only works with foot retention.

The real object of the smooth pedaling game is to reduce leg force variations at the same power as much as is practical for the individual rider. Reducing maximum force results in greater endurance. Thus using EPO gave Lance such a great aerobic advantage that, with endless training,, he could pedal at 110-115 in time trials, greatly reducing maximum pedal force and increasing muscular endurance and thus average speed.

Training is the process of changing the uncomfortable into the comfortable. Starting with the comfortable and maintaining that level of effort doesn't get results.

The above said, it should be obvious that as power increases, the major movers will be able to develop more force at the most favorable knee angles and thus BB torque will become more uneven as power increases, though training to pedal smoothly at lower powers will still have a positive effect on average speed.

It's easy to tell if a rider is pedaling smoothly by looking to see how still their upper body is. I find it interesting to compare the pedaling of say, TdF riders and real endurance riders who operate more in zone 2. Here's a guy riding the old Furnace Creek 508:
Look at that, eh? A riding buddy of mine won it in 29:10 some years ago, It's a tough race.