OCS VS. NROTC. Is there a big difference?

OCS is much shorter and generally much tougher. Somethings you need to consider right now is is your unit crap or are you not cut out to be a military officer? I do not know you or your program and those are just things to consider.

While I'm not Navy, I think I can answer the obvious part of your question.
What's the benefit of ROTC? Getting your college paid for, which is why people go into ROTC, also why people enlist for a GI Bill.
OCS generally is a program for service members who already possess a degree.
I don't see how you would benefit by dropping your scholarship in order to apply for a commissioning program with a boat load of student debt. Your current route will already lead you into a commission and pay for your college.

Mr. Nelson,

Major Rivera pointed out one of the greatest immediate concerns-are you under contract? I assume you're in your first year (4/C), so the impacts financially, academically, and esoterically will vary compared to if you were about to graduate.

Beyond that, I'd like to offer my advice, for what it's worth. If your aspirations still include the Navy, you don't want to "quit" anything...ever. If you're attending NROTC under scholarship, you had to commit some time and effort, not to mention beat out some stiff competition to be afforded the opportunity...leaving the program, even for apparently "noble" reasons will definitely send the wrong message to those you may interact with later in your career. The single best thing you can do to positively impact your future service assignment is to do your absolute BEST in the pipeline you're currently in.

As to how the "Fleet" views your commissioning source, allow me to politely deprive you of some misconceptions. First, all new ensigns share the same first two jobs... learn and qualify. You won't be of much use to your Sailors, your ship, or the service until you do. I don't know what your current aims are, or what aspects of the program are de-motivating to you, but depending on your service assignment, you're looking at up to one-two years beyond graduation before you really even "join" the Fleet. At that point, you'll be judged more by your performance and personality than where you earned your commission. Whether your SWO-bound, or heading to BUD/S, you'll be joining your year group on the even plane of accepting a new challenge.

True-once you've been around a while, there are "differences", but honestly, I've seen fellow USNA grads get RIF'd, while their ROTC/OCS peers were doing the heavy lifting.

As regards training, I can't comment too specifically without knowing what your goals actually are. NROTC, OCS, and even the Academy all have the same basic mission-produce junior officers for the Navy and Marine Corps. A Midshipman at USNA may have access to some programs you don't, and an OCS candidate officer may possess a background that will more positively influence their chosen career path later on...it's all relative. One thing I'm pretty certain you can't do better by switching to any of the three is, "hone in on more training". That's up to you my friend, and nothing's standing in your way but your own determination, drive, and ability.