Unclear. For the first few years of this administration you heard less about it under Peña Nieto, but the estimated numbers keep climbing up, so it is most likely that was media spin for the most part. Also, there is the Ayotzinapa mass kidnapping/murdering of 43 students [1] which happened during his administration and where many people believe the federal government is at least complicit in hindering the Inter-American Human Rights Commission's investigation on the issue [2]. Of course, that is just one anecdotal datapoint (although a particularly shocking one). In general, the feeling is that we got the worst of both worlds: a PRI that is as authoritarian and as hostile to the press as that of the 80's and 90's and yet when it comes to controlling the cartels and local governments, it has as weak of a grip as the Calderon administration did.

Somewhat unrelated, but reinforcing your point about it being corrupt, we keep finding that president Peña Nieto owns quite a few houses he shouldn't be able to afford: [3], [4]

[1] https://en.wikipedia.org/wiki/2014_Iguala_mass_kidnapping

[2] http://www.oas.org/en/iachr/media_center/PReleases/2016/023....

[3] https://www.theguardian.com/world/2016/jul/18/mexico-preside...

[4] http://fusion.net/story/337255/jorge-ramos-another-scandal-p...

Corruption is a super tough problem to deal with. Hopefully cutting into enough revenue streams will give enough of a foothold to begin to combat the gangs.