How Important Is a Starter Cup?

This is my 2nd indoor grow, last time i used peat pots, w hen it was time to transfer i cut it up the side an transplanted into its final pot... i was thinkin about this time putting them straight into the size pot i plan on using... will this hurt anything? im assuming not.. but everyone seems to... if i use my flourescent light i may use a starter cup, but i might put em in regular pot an use MH high up at first.. opinions?

i always start mine in the pot they are going to finish in. keep the light close and leave about 2 inches to fill the dirt up around the stem if you get stretching.

cool appreciate it.. i figured it wouldnt be a big deal.. in my opinion using a starter cup an letting them get root bount it can cause stress, stunt growth, and possibly stress from transplanting..