This is the only exchange I have used to buy/sale BTC, so I can't compare them to other exchanges.
When I first used them, to buy BTC via PayPal, the time to complete the transaction was very long. As I recall it took something like 24 hours from start to finish. The last purchase I made, again via PayPal, was instantaneous. However, the last sale of BTC with cash going to PayPal took several days. This may have been partly due to the time difference between the US and their office. I placed the request either very late on a Thursday or very early on Friday and the transfer was complete Sunday afternoon. They state (or did at the time) that payPal withdrawals are not processed on weekends. They may not have had much time left in the week when my request was received by them.
Other than the time for PayPal cash withdrawals, I have been very pleased with the service I have received. My interactions with the staff , though few, have all been very positive experiences. They claim other exchange types are instantaneous. I haven't tried the other methods, so I can't say that is true. I can say, based on my experiences, that their word is probably good on that. I trust them.