Looking at my list of bikes, I realize how many would be considered "obsolete" by current riders. All are steel -- either lugged, fillet brazed or TiG welded. All have rim brakes, not a disc in the lot. All Bowden cables, no hydraulics. Only four of the derailleur bikes have indexed shifting and it is optional on all but one of those. While I prefer replaceable sealed cartridge bearings, several have cup-and-cones with loose balls in hubs and bottom brackets. There's 2.5 IGH bikes (the traditional U-frame Folder's Sturmey-Archer 3-sp and the Nomad's Rohloff; the factory prototype Folder has a Sachs 3-sp IGH with 7 cogs). Three frames date from 1970. The 1938 bike inherited from my late father has a coaster-brake.
The rest of the derailleur bikes have non-indexed "manual" shifting. Those are all 5-, 6-, or 7-speed cogsets. Four use my preferred half-step and granny gear scheme.
Taken as a whole, I prefer my bikes as I do my motorcars -- manually operated. I'm not a Luddite! Rather, I like the involvement, the requirements that I need skills to operate them smoothly and the reward structure built into acquiring those skills and that translates into long service life. I typically get a lot more use out of my older drivetrains but can easily burn through a crossover 9-sp chain, chainring and cassette in a summer. On cars, I typically manage close to 300,000kms on a clutch and original synchros in a true manual transmission. At present, I'm driving a car with 177,000kms on a dual-clutch, dual-gearset manu-matic and it is laid-up awaiting a rebuilt Transmission Control Module.
It doesn't hurt that are all my derailleur bikes' drivetrains are long-lived and easily repairable to keep going (I reprofile the thick cog teeth and retemper/quench when they become hooked, easy enough since they are non-indexed). One of the major appeals of the Rohloff for me was the long service life.
So...how important is "rider involvement" to you? Do you prefer it as I do, it do you like the bike to be as unintrusive and uninvolving as possible? I know I love my Fixie, but that cuts both ways. It is at once incredibly involving (when not pedaling, the bike pedals me) and also as simple as it gets.
Best,
Dan.