Promo System
After playing ranked for a significant amount of time (300+ games), I've found a pattern. A promo series is significantly more difficult than a normal ranked match.
This is logical, since it is a "test of skill".
However, there is an issue.
Upon reaching a promo series, I have won 3-5 games in a row, within the division, in order to gain the LP required to advance. However, after going on these winning streaks, I find my games to be set with everyone on my team in the same promo series (in my recent cases, b5 >> b4), and everyone on the enemy team already in the next division.
This is frustrating, because a promo series is stressful, and stress significantly effects your play. For one side to be completely at ease, with no punishment for losing (other than LP), and the other to be anxious, the series becomes more of a game of luck, where you hope that nobody on your team is on tilt from a previous bad game.
My suggestion is that games in a promo series should include only people that are also in a promo series, on both sides. Obviously, this excludes challenger, diamond, and plat promos, due to numbers, but at low Elo it becomes frustrating to lose a series because of the pressure one team has on a match, that another does not.