I've read the announcement and have to admit that these are potentially very dangerous changes in my opinion. I even start to feel uneasy trusting Bitfinex with the sums I have deposited there.
Let me explain in detail why I feel these changes are not positive at all in my opinion.
1. The fee structure for trading seems fine. It's a popular model although I think offering something like the Vault of Satoshi "flatrate" would have been even more attractive.
2. Previously unannounced percentage fees for fiat withdrawals. Bitfinex, are you kidding me? With this changed you have just stated that our money is basically trapped at Bitfinex. I chose BFX because it had NO percentage withdrawal fees with a reasonable fixed fee which was just doubled as well. What if you suddenly announce tomorrow that the withdrawal fee is one percent? Considering the already obscure international wire transfer system this makes fiat withdrawals extremely unattracitve closely to obsolete.
3. Change in the swap fee structure and insurance: This is by far the biggest and most dangerous change. You have just increased the fees by 50 % for the removal of a feature that was basically never available and not thought out at all. If you had provided completely transparent insurance I would have gladly taken it for 30 % but insurance was always a mirage.
"Another reason for removing swap insurance is that we have decided to effectively insure all swaps on the platform."
I take this to mean that all swaps are now ensured by BFX and that the enormous total scandal fee hike for lenders is meant to cover this. I'm not sure why the word "effectively" is there, though. It's really binary, either swaps a) are insured OR b) swaps are not insured.
I can tell you what that means. It means that BFX tries to make lenders believe that their swaps are insured when there are actually no sufficient funds to insure the swaps in case of a serious crash. They just assume they will be able to halt (manipulate) trading fast enough for nobody to be able to close their shorts in time.
This is extremely dangerous as it basically takes the "indifferent for BFX p2p lending" away from the platform making it BFX the liquidityp provider who borrows the money to lend it out. We have seen how BTCe has handled the flash crash and why this change adds serious counterparty risk.
On top of that the illusion of insured loans will lead people to offer more swaps hereby increasing the supply of swaps and mutually decreasing the lending rate. The decreased lending rate will encourage people to more reckless margin trading and actually increase the risk for flash crashes.
"effectively insured" is a really dangerous term and I just can repeate that these changes have made BFX a whole lot more untrustworthy for me.