Similarities/differences
1. You'll be wearing the same uniform daily, but pick up a lot more uniforms (and accessories like a sword)and have to get them tailored/inspected.
2. You'll be at Quantico again, but on the other side of I-95.
3. You'll drill, march and run, but be working out more on your own and marching further and "camping out" more often as well as getting really proficient at Land/Nav.
4. You can bring a car, but you can drive it daily (if not camping out).
5. You'll have Marine instructors, but ratio of enlisted/officers will be reserved and you'll get far more officers instructing you.
6. You'll be rising and shining as a team, but get more privacy in the head.
7. Still won't be immune from personal, equipment and room inspections, but you're an officer at TBS and will be expected to keep your s___ in clean and in proper condition so they will be less harsh and less frequent.
8. You'll learn and be exposed to weaponry of the Marine Corps, but you'll have a lot more hands on time and get familiar with and be tested on a lot more weapons.
9. You'll be surrounded by your peers, but you'll be in a sea of 2/LTs at TBS with better living situation and married Marines go home at night.
10. There will be pressure to excel and perform under observation, but OCS is a selection tool/process and not all are expected to survive and proceed to TBS whereas TBS is a training environment and you really have to work at it to not graduate. Marines would be happy to graduate 100% of every class.
Note: My any and all observations are now 30+ years old (some things may be the same and some different...ie I enjoyed my TBS experience and the friendships I made there)