You have to buy and use whatever system works for you. I grew up with friction shift, which I use exclusively. (I'm even the guy who friction-shifted a Sturmey-Archer 3-speed coaster hub with an old Huret friction downtube lever.
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I particularly like friction's ease of accommodating any mix-and-match combination of cogs, chainrings, chains, and derailleurs. Changing from 6 to 7 cogs or from 7 to 8 cogs in back? Been there ... done that. Easy. A bit of cable stretch? Just pull the lever back a bit more until you get a chance to readjust the system to accommodate the change (if necessary or desired).
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069