Originally the IF dataset was dispatched by NavDataPro as Flight1 Europe is affiliated with them. Dispatching from Navigraph was held off for a year or so.
During that period of Ideal Flight development, codelegend navdata scanners found errors in most common datasets which have since been improved across the board. You can check this with Aerosoft, I still have the mails concerning the improvements.
So in fact all your navdata sets including PMDG, Level-D etc. are all since improved due to Ideal Flight development.
Navigraph were going to put it in but I told them to wait since back then Dovetail Games was in the mix with FSX:SE and FSW and the future of IF was not completely mapped out.
The upshot is that Navigraph are still waiting on me - sorry chaps will get in touch soon!
Anyhow:
You can install PMDG, iFly, Level-D and AXE datasets in any folder you like or make a folder in:
"C:\Program Files (x86)\Ideal Flight Professional\Navdata"
Even though it's in program files you will find you have permission to the \Navdata folder as IF set's up proper permissions during the install.
Then in the front IF page popup menu use the folder picker to choose one of the PMDG, iFly, Level-D and AXE data sets.
So if you download an AXE or PMDG etc Navdata set you already have an IF dataset ready to go.
When using the PMDGs I use the PMDG dataset to make routes from, this data is compared to the sim navdata (the actual navigation data in your sim), and is also compared to fsAerodata if you have it installed.
Since aircraft that use navdata sets don't know what's in the sim - doing it the Ideal Flight way guarantees a plan that contains navigation data your plane understands.
Note: The IFPro dataset is the same as the AXE.