Was going to suggest you to see if someone would swap you for the .68 head, but I’m glad you got the hang of it now!
I wasn't pleased that Italian Barber eliminated the 0.68 for the 0.84 and the reason was that it made more sense to only stock up what they could sell easier, which begs the question why continue making the mamba then?
Regardless, the 84 is a decent razor but for those who prefer mild razors, the 84 steps into aggressive territory and care needs to taken when choosing the right blade.