I already buy one Giant plane with coins and one with tokens.
The reason why I buy Giant plane with tokens is because I can save my coins for other purpose
But I also buy one Giant plane with coins because if the Giant S1 plane broken it will cost 1 green cash to speed up the repairing
greensmith nsari - etal- I recommend you spend your tokens getting the Giant SI planes rather than using your coins. I bought 3 normal giants (900k) rather than use my tokens (in hindsight a silly boy). I can tell you that when the Giants brake down it costs 2 greenies to speed up the repair. S1 planes only need 1 greenie to speed up repairs (if you don't want to wait).
Hope this assists but if I had my time over I would definitely use the gold/silver tokens