Some thoughts:
Since "KP" no longer scales with placement, the new system greatly discourages fighting, and conversely encourages ratting much more strongly than the current system. Right now, after reaching Platinum 1 or so, you gain zero to negative RP if you get zero kills/assists in a match, even if you rat to 3rd place. Compare this to the new system, where you will now earn 150 LP (i.e. 15% progress towards the next division). Keep in mind that this will apply whether you are in Bronze 4 or Diamond 1.
This means there is no more roflstomping your way up the lower ranks, because:
A). The MMR matchmaking means the teams you face will always be close in skill to your squad,
B). The rank you are in no longer influences the teams you are placed against.
That means players who favored racking up kills to gain RP (even if they are highly skilled) are now at a massive disadvantage. They will either score a bunch of kills against lower skilled opponents (which earns ...