I should also add that the date on the smackpack, along with the intended OG of your beer, will also affect whether you should make a starter. For example, the 1056 smackpack I picked up today was manufactured on July 19th... according to mrmalty.com, that means that the viability has dropped to 66%, so even for a measly 1.053 APA I plan on making, they recommend a 1.77 L starter (intermittent shaking).
Starters are easy to do, they just take a little time. As long as you can plan your brewday in advance, you shouldn't have a problem.