I don't remember the A/C belt being an issue. IIRC, I removed the fan and airbox.
I trust Dinan more than the other products and I got this lightly used for a pretty good price. Not sure if I can feel any difference though.
2015 F34 328iX GT Glacier Silver
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red