I can safely say that you will buy SWIFT, i have kept one. you won't regret it. i have kept Vitz also. you are right about fake milage, change of all oils right after purchase, parts are costly, electronic sensors are not easily available. just to give you an idea, my vitz AC compressor got faulty after a car wash. it cost me 20,000 to replace it. i had to change balancing rods, costed me 3000. both on Suzuki Swift will not be 10,000 and 800 respectively.
Swift is not that bad in comfort, seats are large, black interior is quick in catching dust and therefore requires more maintenance, same would be true for Vitz or Passo that has black trim. Swift interior finishing lacks quality - that you will accept since its a Suzuki. any moter mechanic can fix it, hence no trouble after 5 years.
Selling swift is quite easy, mine got sold on 2nd day of putting AD of pakwheels, selling 10 years old Vitz means you will lose some money and it wont sell real soon.
one aspect is about radioactive elements present is JDMs, few cars imported are from the area where Japan had neuclear plant that got damaged due to fire. if you land up buying one of those, you will surely regret your decision.
my suggestion to you is GO FOR SWIFT
