Hi PB_783, sorry for the delay in response.
All schools state that it's better to submit a great application in a later round than a good one earlier. So if you feel you can make your essays better, then I would take the time to do so and submit in R2. The essays matter A LOT.
There is an advantage in R1, however, in that there are just more open slots. If a school's R1 apps are particularly strong in a given year, then there will be fewer spaces available in subsequent rounds (obviously). So there is some risk in coming in later.
Hope that helps!
Lisa, Columbia MBA | Admissions Consultant | Elite GMAT Preparation and Admissions Consulting | http://www.VeritasPrep.com