Enlist or national guard then switch?

I want to join the army as a linguist or something in the field. If I outright enlist after graduation I will be E4 and get a signing bonus. But I will have to sign a contract for something I'm not even sure I like. My national guard friend is telling me to go the national guard route to test the waters, and then if I like it I can transfer to active duty. I am pretty sure I'd have a smaller bonus. I have a personality where I get bored pretty easily. I might be bored being stuck in to a job for the length of my contract, or I could be bored from not being in the middle of some action. What did you guys do, were you in a similar situation, and why did you choose it that way?