One issue you may have with DPP is that if you have been shooting for a while your older cameras may not be supported by DPP4 so you may need both version 3 and 4.
If you make much use of the Lr DAM features for managing your images, as well as the develop module for processing them, DPP will be no match for Lr. Personally with large numbers of images from camera's that are not supported in DPP4, and a mostly RAW only workflow in Lr, where I only create output files as needed having to use multiple versions of DPP would be a non starter. I moved to Lr from a Bridge/ACR/Ps workflow because of the number of RAW/PSD/JPEG files I was having to juggle and try to keep up to date.
If I were in a position where I had to deal with new cameras that were not supported in my version of Lr I would go with the DNG conversion option. I would keep a copy of the CR2 (or other file type) in my backup archive, but I would just work locally with the DNG's.
I had to move to CC last year, my new computer came with a 5K monitor, and you need CC to properly support that screen resolution. If I were in the position of needing new camera support only I would like Wilt have gone for Lr6.
I'm pretty sure that while Adobe continue to use Process Version 2012 they will carry on releasing camera updates for Lr6 without exposing the new tools in the interface. They do something very similar between Ps and Ps Elements (for current versions), where they limit access to certain tools in the Elements version of ACR, while the PV2012 engine is identical in both. If you process an image in the full version, or add the instructions to the xmp file by hand, the Elements ACR will run the conversion without any issues.
Although currently you are doing the conversion to DNG manually it should be very easy to make a script that will automatically do this for you. This should actually be easier on OSX than with windows, since OSX is based on the BSD Unix clone.
Alan