Poloniex and Bitfinex both have withdraw delays or not processing all together
Where did you get this info?
Just a few days ago, I tried to withdraw a few litecoins, and the withdrawal was processed pretty fast (within a few minutes). Indeed, I don't know what my mileage would have been if I had tried to withdraw a few thousand litecoins (or bitcoins), but if there were numerous issues with withdrawals at Bitfinex (obviously, apart from fiat withdrawals which are disabled right now), there would be a lot of noise across the forum (and in this thread specifically). Other than that, I agree with you that withdrawal issues are a telling sign of possible problems in the future. It was the same with Cryptsy, and it had been constant delays with withdrawing even tiny amounts that finally made me abandon this exchange for good. That turned out to be a wise decision in the end