For anyone reading this down the line, there is one other major issue not yet mentioned regarding QFN vs QFP when it comes to commercial production of boards - and that is reliability.
If you have a product that deals with lots of thermal cycling or other vibrational/mechanical stress, leaded parts are the way to go. Leadless parts look neater, but don't always take up less space since there's usually a big thermal pad that you can't route signals through. If you're going to produce a thousand boards that will see a rough life (outdoors, automotive, etc), leaded parts generally last about 10x longer than leadless parts before you start to see issues with cracking solder joints, etc.
I work as a EE in oil and gas, formerly aerospace, and I swear against leadless parts in these applications for this reason.
Of course, you can always take additional measures to help even the playing field (primarily potting your leadless ICs), but this doesn't guarantee that you're giving your parts the same longevity as a leaded part. Additionally, this will typically make your leadless implementations more expensive due to the additional manufacturing steps required.