No, not a complete flop.
I'm not really liking it so far though.
HoI2 was nearly perfect imo, top 5 games of all time for me. It had a perfect balance of depth and ease of play.
The threat/neutrality system may be more realistic, but it feels really sluggish to work with. Same goes for drift. In HoI2, sliders were nice and straightforward, once per year you can do whatever you want with a few limitations. It didn't take any extra management and while it may not have been super realistic it was good from a gameplay standpoint.
I also miss the tech teams alot. In HoI2, you could have Porsche develop your tanks as Germany, Yamamoto developing naval doctrines as Japan, etc, and it was REALLY sweet, it added some color, flair and personality to the system. But now, in 3, we just have a massive excel spreadsheet for teching. And it's just so sterile and drab.
That's the feel I have in general. HoI3 just seems more like an excel spreadsheet with a ton of extra stuff, statistics for stuff I don't give two shits about, etc, stuff tacked on that apparently make it more realistic. Realistic at the cost of ease of play, style and fun.
I wanted to mod cores but apparently each province has its own file now, so instead of taking a few minutes it'll more like take hour(s) to edit each file in turn, especially since there are 913543543 provinces now. Sucks.