You should read more about AL. But in short, yes, you should use it. It is much easier to find investors, and if you win one over, it is easier to extend out from their personal networks as well. I'd also recommend you start reading venturehacks.com.
http://onstartups.com/tabid/3339/bid/63010/Raising-Money-On-...
If you can get 1 key investor or endorser, you're pretty much in. How do you get that key? Usually from networking in person, or by having stellar metrics that people can't turn down at least talking to you.
With that said, you need to be aware that going online, setting up an AngelList account and spamming investors won't get you anywhere either. I think AngelList is a tool and it's up to you how to use it. Combined with "old fashioned" networking AngelList makes it much easier to get a seed round (or series financing) together.
You just want to make sure that, if nothing else, the investors you contact on AngelList have at least heard of you somewhat, or someone they know has. You can meet them by trying to go to events where these people are speaking or hanging out. Talk to them about your start up, maybe set up a coffee date. Once you've talked a few people (don't even mention fundraising at first!) then drop the hint that you guys are looking to raise some money. AngelList will then provide the gears, but you've always got to be the engine!
Just fill it out. Worst comes to worst.. something comes out of it.