TBH, the location of voco Stockholm is only good for business travellers visiting any of the tech companies in the Kista area. For tourists, the centrally located Strawberry hotels are a better Choice...

The only reasons for anyone to book the voco without business in Kista would be if the savings from lower room rates are valued higher than the time to travel to the city centre (or wherever you want to go), or if there's a need to gather IHG nights/points. The latter would be my reason, if I decide to go for it.