if you searched you could probably find this exact thread repeated every few years. The answer is always that it depends.

Best performance and reliability?

classic record, dia-compe gran compe or royal gran compe, superbe (all of these are very very similar) and of course the best, really the best is dura-ace 7400.

Now, just like the brakes of today these are not all the lightest brakes, so if you bring weight into it, it totally changes.

Record was produced from about 1968 to 1984 and then till 1987 in a slightly updated aesthetic but more or less unchanged. These spanned the golden era and probably were the winningest brakes in the 1970s. To me they will always be the best vintage single pivot sidepull, I even use them on my bike with 10 speed chorus and fenders with old mathauser pads.