Pre 1950s rides of LFGSS: old bikes, vintage rats, classic lightweights

Surely the significant difference between one pedal and another is their condition. Aside from the obvious - rust, knackered bearings and cages falling apart, there is the problem that the spindles may be bent. It's only too easy to damage a spindle - I once ruined a Chater spindle by hitting a traffic cone (forced into it by a skip lorry). A bent spindle causes the pedal to feel as though it's twisting under your foot, but unfortunately you soon get used to the twisting and cease to notice it until you get on another machine with straight pedals - and then the 'true' pedal feels wrong. The same problem applies to cranks, and it can be hard to tell where the fault lies; pedal or crank or both.

Unfortunately your knees will not fail to notice that something is wrong, and this is a classic cause of cyclists' knee problems. Graham Webb (World Amateur Road Champion 1967) attributed his lack of success as a pro to knee damage caused by a bent but unnoticed pedal.

Another issue is the length of the thread. Pedals for steel cranks have a shorter thread than for ali. It's possible to use the wrong combination, but a steel type thread in an ali crank is thought by many not to be safe (failure of the crank at this point is not rare and can have disastrous results), while a long thread in a steel crank will result in an ugly projection which may have the potential to catch on the chain.

So my conclusion is: don't worry too much about the brand and don't pay exhorbitant prices, just try to find something that will work for you and your set up. Pedals are both critical and expendable.