I think one of the problems the CPL teams have had is the gulf between the top 4-6 teams, the mid-tier and the lower end of the division - for 3 of the events, the semi-finals had the same 4 teams, and was only different in Paris because those top4 teams met in the quarter finals instead.
The mid-tier has been shaken up a little this season with newcomers Scorpions Milano, PP Arena and Drammen Solid performing strongly, but the seeding system meant that you could pretty accurately guess 6-7 of the 8 teams that would be in Sunday Club, leaving the other teams to fight for scraps. The aim for the lowest teams in each group only seemed to be to beat the 3rd ranked team to help avoid relegation at the end of the season, and to hope that with a slightly higher ranking maybe they'd get an easier group next time. If they could beat the top or second seed in their group that would have been a huge bonus.
Splitting the division in 2 and increasing the number of games makes it more worthwhile for all of the teams to be there - Champion teams have more interesting/challenging games, Challenger teams have something to play for and everyone gets more field time for the investment in time and money they've made to be there.