For those that haven't had a chance to play with the Colt Centennial pair it is the only modern Colts that had a real V notch rear sight and a tapered blade front. Sadly not a lot of those guns made either. All the 3rd Gen BP framed guns have a U shaped rear and a standard front sight. So those frames aren't actually traditional BP Colt frames either.
Most that are used to the sight picture on a modern gun think the current Colt U notch and the melted edges of the standard 3rd Gen SAA front sight are bad. And they are, by any modern comparison. But still they are way, way better than the older V notch and tapered blade of the pre 1931 guns.
Square Rear Sight
Production Dates 1931-1940.
And again in all of the 2nd Gen with the rare exceptions (the Centennial guns being the only exception I know of) The U shaped rear sight continued through current production 3rd Gens, again with rare exceptions (maybe only 125 guns with a true V).
V notch and tapered front is certainly an acquired taste now. But that tiny V notch rear and tapered front blade is the "traditional" 1st Gen sight combo on the BP frames or earlier smokeless frames.
"V" Rear Sight
Production Dates 1873-1931