The only downside is that you have to be willing to wait and keep your balance blocked for 365 days for a 60% APY (fixed-term).
I have checked and found out that in order to get 60% APY (boosted fixed term), you need to fulfill some wagering requirements as well, while in fixed term (27% APY), there is no requirement of any wagering.
How much wagering.
IF I put up 1000 and get 27% it is 1270
If I put up 1000 and get 60% it is 1600
Must I bet 100 1 time
Must I bet 100 2 times
Must I bet 100 3 times
Or could I bet 10 1 time? Not likely this little of a bet.