I'll be gold next month, to make platinum I'd have to do a couple mileage runs or equivalent for about $800. It looks like there are significant benefits to being gold over silver (100% instead of 50% mileage bonus, possibility of companion upgrades, an even better elite line, priority in line on domestic upgrades, where silvers often miss out). But from what I can tell if I become platinum the marginal difference between it and gold is only:

1. another 25% mileage bonus on miles flown
2. waiver of the $50 adminstrative mileage rebanking fee (but you still have to pay a $200 per ticket change to an upgradable B international ticket)
3. First instead of 2nd in line for domestic upgrades (but from what I've read on other threads, golds still have an excellent upgrade potential).

But you still don't get priority in getting upgradable international fares or awards.

So for those of you who went from gold to platinum in recent years, did your flying lives really change all that much?