Setia Sky VS The Robertson

Always select according to accessibility. Things like shuttles often stop after a while and may not run when required or be full and no seats at a specific time). Choose the best location according to access to  public transport and convenience to workplace and basic amenities such as shopping. Traffic is bad around KL so being close to daily destinations will ease the stress and time wasted.

I know both locations well and would say Setia SKY is most convenient to KLCC. The Robertson would be more convenient if working out of the City Centre say in Mid Valley or beyond as its on a busy exit road.  If working in BB, then the Robertson may be more convenient although the road system may make the shuttle slow. The facilities around Setia SKY are probably a bit more superior to those around The Robertson. Crossing Jalan Pudu is a bit of a nightmare. Safety-wise, I would say Setia SKY

I'm curious you think Setia Sky is remote, because its right in the heart of the city. But I guess it depends on where you are trying to get to. It is about a 10-12 minute walk to the twin towers. But there are nearer facilities.

GM Plaza looks to be a more cut-price Mall along the lines of Times Square - living in KLCC is probably going to be more expensive.

So choose based on convenience to your workplace and pocket.