Sony drawbacks. Too complex. No spare parts support. Very nice performing when working. Automation sometimes gets in the way. It's a classic. No real tweak or upgrade possibilities. I'd get a pivoted Sony Biotracer over the Linear tracking versions, less to go wrong.
Dual drawbacks. Expensive spare parts. Budget for a Bohhey style overhaul on it every 5 years of use and if you want one buy it from him. Or send yours to him. Cartridge Mount prone to some issues with connections (last style cartridge mount better on this area) Spare mounts expensive a la Thorens headshells ($60 upwards to as much as $100)
Technics drawbacks. Some worked for a living. Some treated better than others. Technics has more advantages than disadvantages. It's durable, reliable, performs well, can be tweaked to amazing levels. It is less stylish, more business like.
General advice, Technics is a more practical solution for many. I like the Sony best in pivoted arm livery, I like the Biotracer arm except for repairing one. Dual is one of the best changers, but leave them for those who need changers. Sony's technology can also be had in JVC and Denon variants too, consider them. Technics will also be best supported on spare parts, service, and upgrades.