Be specific as to what area you are willing to work; some hospitals interchange ICCU and telemetry. I always specify ONLY ICCU ( some tele units are horrible to work in, not strictly tele patients and poor staffing ratios).
Agency nursing is good because you are not involved in any politics or unit battles. You schedule according to your needs ( a huge incentive to work agency!).
You may not get the intresting patients if you are agency. The hospital may not know your capabilities and you won't know their policies/procedures, or where things are kept that you need. You may get the demanding or unpleasant pts ( constant stooling, etc). I look at it as it allows the staff nurses a break and I'm getting big bucks and I can handle it for 8 or 12 hours.
Also take into consideration that you can be cancelled so your income will flucuate. Some agencies have noncancellable shifts but those are usually at undesirable locations or a contract situation.