Like you I didn't understand what ROTC was about back when I was heading off to college. I figured if I was going to be an officer I wanted to be a "real" officer, so I tried the service academy route (only one school, only one congressman... now I know that was too limiting).
Back on track. ROTC will make you a "real" officer just like any of the academies. I'm fairly certain that there are more ROTC and prior enlisted OCS officers than West Pointers, if not it's a fairly even split. I've see great officers, average officers, and terrible officers from each commissioning source; none is better, just different.
I'll speak from the Army side, small details have probably changed over the years as I graduated in 2001.
Commitment is 8 Years. This is for every service, officer or enlisted. In the Army only 4 years has to be on active duty, the last four can be on active or inactive reserves. If you want to go aviaiton, then you have a 6 year commitment effective the day you finish your initial flight training (comes out to be about 7 years total active, training plus the 6).
I recommend applying before you go to school and not after you get there (4 years tuition plus books and room and board vs. 2 or 3 years tuition and books only). On scholarship you also get a monthly stipend, yours to spend on food, beer, or girls. I didn't have room and board and only a 3 year scholarship (showed up without one) and had to get a part time job while I was in school to cover food, rent, fun, gas, and the girl.
As a freshman and sophmore you will have one hour of military class per week and a 90 minute leadership lab once a week. You will also go to the field once or twice a semseter over the weekend where you will do land navigation, basic rifle marksmanship, obstacle courses, and learn small unit tactics. Your third and fourth year you will have three hours of class a week. Your third year you will also be evaluated on leadership and prepared for a summer time exercise where you will be evaluated on your leadership potential. Senior year is where you are really put in charge of the cadets, conduct the training, and develop the juniors.
Your future job will be based upon the armys needs, your preferences, your GPA, your summer camp score, and your on campus military performance.
If you show up without a scholarship, go to the orientation briefings during your "welcome to college" week before college really begins, talk to the instructors, decide which service you'd be most interested in, and sign up for the freshman course. If you want a scholarship then make yourself competitive. Get a good GPA, show initiative and interest, and volunteer. I volunteered to help out on one of the Junior only training exercises as the opposing force (enemy soldier). I also joined the colorguard squad and presented the flag during soccer, voleyball, and basketball games; participated in a couple of parades, and presented the flag during the national anthems during Daytona Speed week.
Best of luck with your decision. I'd be happy to talk about the Army if you are interested. Do your research, and it never hurts to apply. If you apply, apply to all services ROTC programs. Better to have choices than a "small envelope" waiting for you in the mailbox.