I work for a large commercial bank in a branch and what I've noticed is that the level of consistency for people dealing with fraud on their accounts and having it resolved quickly varies. Most of the time people are called when charges come up and it's clear that that wasn't them, such as a charge coming from NY when you live in CO. Usually under these circumstances the customers are immediately given credit while the investigation is going on, similar to how most banks will give you credit for deposits prior to checks actually clearing. FYI: The actual clearing process for most checks, even if local, is at least 2 days because of the way it gets routed manually, and if it's out of state and in a state that's pretty far away from you it can take up to 7 business days, so don't get pissed off at tellers when they put holds on your funds, it's prompted by the system and yes it really is necessary to ensure that the check is going to clear...unless you want to take the chance of it bouncing and owing the bank $$$ in OD charges.
Anyways, the larger your bank, the better (usu.) their Loss Management/Prevention and Fraud dept.'s are. Ours are pretty good, there's a dept. that watches check card fraud in particular and the system flags suspicious transactions, it prompts a person to call you and verify that it was or wasn't you and if it wasn't then that's where the investigation starts. But, I have seen some instances where the customer doesn't get immediate credit and they have to wait until both banks (custies and the business that got paid) LP dept's agree on the fact that it was fraud. In those situations it's usually because the customer is new to the bank (new is up to 6 months at my bank), and/or has past fraudulent activity which makes additional activity at a recent time very suspicious. Check cards these days are pretty safe unless you're being careless about things. But like people have noted, I think the general rule should be, if you have to let your card out of your sight (restaurants are a big one), then try to use a credit card, whereas if you're almost always in contact with your card and are watching the person swipe it, then it's probably pretty safe to use your debit card b/c that person doesn't have the opportunity to take down your info.
One final note, I think this is a given for most of the CAG's but you should avoid using checks as much as possible. Why? Checks have your name, (usu.) they have your address, it has your bank and most have the branch that you started your account at which is a good sign of where you bank, sometimes people put their phone numbers on them, they have your ABA/routing number, account number and even what check sequence you're in. Checks are by far the WORST way to make payments unless they're to somebody you know and trust...yes they do offer a way to trace your transactions but they have everything somebody needs to get into your accounts and they don't even have to ask you for anything. Know how most stores need your ID information for checks too? Guess what, once you give them that, they now can even spoof your ID with all the correct info...and that makes it damn hard to trace them.
Credit Cards > Check Cards > Checks