Both are different and each has advantages and disadvantages.
In Font Nav, I had more control. I could scan my folder(s) containing all the different font technologies. I could EASILY see through Font Nav I had installed and which were not. I.e. if I didnt want use old Type 1 fonts I could EASILY uninstall them without deleting them from my huge collections residing in those folders locally.
Now it seems CFM automatically loads them when I open a CorelDraw file. It doesnt let me NOT use certain fonts. I.e. I may want to use a TrueType tech font instead of Type 1? It almost forces me, as it somehow in the background loads that Type 1 font when it opens the cdr?
The workaround, (And why do I have to use a workaround when it has been working just fine for YEARS?) is I either have to delete the Type 1 font I do not want Corel to "automatically" pull from, or I have to compress or zip those fonts so CFM cannot pull them for use. I would have to do this for all of them this way?
FontNav just worked. It wasn't broke, so it didn't need fixed.
I am all for progress and newer better features, which I do realize CFM has advantages and disadvantages... but this automatic stuff is a disadvantage for me personally.
Ever since the first Windows 10 Creative Update, Microsoft has really messed things up if you use from a large collection of Type 1 fonts. If there are any Type 1 fonts used in your file (EDIT: Myriad Roman) , when you copy a single text item that contains Type 1 fonts, then there is a DELAY. (CorelDraw X7, 2017). If you remove all traces of the Type 1 font in your file, it returns back to normal speed without delay.
CFM keeps loading Type 1 fonts when I open the cdr. So I have to use a workaround and/or font substitution and save the exemption. FontNav just had more control.
Also, duplicate fonts create havoc. (EDIT: i.e. CFM sees Myriad Roman (Type 1) AND Myriad Roman (TrueType) it will show as GARBLED text)).