I'm looking at both bikes as next options. Both are basically the same price with the 2016 S being very slightly more expensive. 2013 R. 25k kms. Ohlins, carbon etc. zard exhaust. 2016 Speed S standard model. Riding modes etc. 15k kms. Arrow exhaust. Any real difference between the 2? Worth going for the newer model? Note: I've owned a 2020 765RS, 2016 Street triple R and a 2013 Daytona R. I dont care about power but at the moment it's all I can afford.
Personally I would go for the 2016 S model, it has a lot of engine mods from that of the 2013 model with better throttle response, ride by wire throttle and rider modes, overall it makes for a nice comfortable ride. However you say you have owned a Street Triple 765rs and for me that machine is a lot more fun to ride, and it is only marginally slower than the Speed Triple top end, you do gain on more torque with the Speed Triple with not as much up/down shifting, some 2013 Speed Triples had gearbox and clutch issues, but not all machines suffered from this, the 2016 model has a revised gearbox and clutch, a lot had issues with the optional quickshifter as well (no autoblipper on the 2016), although your 2020 Street Triple 765rs had the up/down shifter. Good luck with whatever you decide.