Pros
Up through E-5 you control your promotions through your composite score and you learn how those points can be attained in boot camp. Aside from the proficiency and conduct marks, the rest are completely in your hands. It is good to know that there is no "hook-up" pertaining to a lot of those promotions. Everything is earned and not given! I find that to be something that is very appealing about the Marine Corps promotion system. The benefits are an outstanding reason to join. 30 paid days off a year from the first year in the corps, find that somewhere in the civilian world! Our history and ethos is also something that you won't find in any other organization!
Cons
Unfortunately both in the military and civilian world it only takes one person to ruin a unit or company. If some people find a way to just lay low and stay out of trouble they can eventually be promoted into a position that is well above their level of comprehension and ability to perform at the necessary standard. Too often there is a percentage of Marines who are in a position where they have a significant amount of power over subordinates and can adversely affect their career for reasons that should not enter the decision making process. Jealousy can work in both directions, especially in the Marine Band field where a level of musical proficiency is very easy to determine who is better or more qualified by the product that is produced through something as obvious as daily performance. Once again, some people who never have been able to meet minimum standards just lay low long enough and are not able to make impartial decisions without bias or personal agendas. When it is your word against someone of senior rank's word, especially pertaining to something that is of a subjective opinion, then there not much of a realistic forum to get things changed in to the way that they should be. RHIP (Rank has it's privileges!) I've worked for superiors who were all around amazing senior Marines(officers and enlisted), and I must note that they were all immensely proficient and open for suggestions at the right time and right place. Although there is a certain percentage of lack luster and abysmal Marines in senior positions that I have worked for, there seems to be a very significant trend, that is that they couldn't do the job at hand themselves and produce a quality outcome and these types of leader have the "my way or the highway" mentality. Taking the suggestions of their troops or fellow leaders is mostly not an option because they want all the glory and all the power now that they finally are getting a taste of it.