Nothing new in 5 years 
- Rocker Arm Bearing Failure: I've noticed a few gumtree Enduros in the 2008 range with "rocker arms redone". Is this an issue?
- Low speed stalling: Seems to be linked to dodgy mapping. Doesn't affect all bikes. Schlowy's accelerator module or a pricey Vortex ECU helps but RAD can work on the stock ECU's mapping.
- Accelerator lag/Twitchy throttle: Aftermarket accelerator cable?
- Air box: Need to seal the air filter to the airbox with rubber grease or fit a Unifilter. Runner sells it.
- Routing of the fuel line: Underneath the seat alongside the air intake box. (between the air box and frame) The line tends to rub through due to vibration on a frame bolt.
- Headlight globe failure: Probably due to vibration. LED globe would likely help.
- Wiring: Is fairly naked close to connectors and can rub through causing a short. Insulation tape fix.
Is that it? I'm curious about these niggles that were solved on the 2011 models.
I've had my 2017 now for 1 year and 10 000km.
I did the Insulation tape fix on the rear for rubbing, I did the preventative fix on greasing the airbox.
Not 1 single issue - miles of smiles only. Best bike I've ever owned and i've had a few. I ride it hard but keep it well maintained. Correct torque specs and correct oil etc. i.e I follow the maintenance requirements to the tee.
If you want to get a 690 just get one. You will be happy you did.
Rocker Arm BearingsRocker arms bearings were an issue in pre 2014 models. They wore out making the rocker arm pin to slide around...when worn enough it can slide out a long way and the rocker arm then hits that and...well it brakes if you are lucky or shatters catastrophically if you unlucky. Mate had one go catastrophically on his 2009 model at iirc 27 000km The bill was R16000 to replace everything with new parts.
2015 and up they had a redesign and this should not happen anymore. If you are worried replace the rocker arm bearings every 25 000km for +- R1200 as part of your maintenance.
So if someone did the rocker arms or rather rocker arm bearings thats a good thing imho.
Low speed stalling - That's a user error imho. No problems here. 10/10 times the owner changed the exhaust and airbox. You can do that but there are things to consider. I run a Wings exhaust and stock airbox. Medium baffle. Anything more you have to re-map. Then you have all kinds of variables from mapping to the guy doing it etc etc.
Accelerator lag / twitchy throttle = Either have the underseat throttle map switch on Bad fuel/Low power setting (Laggy) or on High Power setting - Twitchy. Set it on Medium and it's smooth in my experience. It's a 690cc Thumper with a big fat piston - It's not going to ride like you are riding with miss daisy on the back. That or you are holding on too tight
Airbox. People over-tighten the bolts causing a gap in the plastic bit that keeps it down it's 10n/m - that's finger tight only - that and/or they don't take care to clip the front piece piece into the bracket properly, or think they did but did not. There is a trick to it and I once checked my mates's one who was just at KTM and they did not even clip it in properly. Check it! I sealed it with grease or Vaseline around the edge anyway. Clean as a whistle.
Globes All globes and lighting still fine as well as dash and I've taken it over a lot of rough terrain, dust rock sand rain, etc.
Wiring. Checked all the wiring when 1000km on it. All wiring perfect except rear light wiring that I see could shafe a bit... So I re routed it slightly and put tape around it. 9000km later, all still good.