For myself I am stupefied to see almost everybody relying blindly on commercial stuff.
Personally I don't, other than Pooleys. And if I'm not convinced by what I read there I go and check in the AIP or the airport's own web site. As others have indicated I am hoping and expecting that this process would count as having done due diligence.
But I'm not convinced that using some freeware web site or software for weather or NOTAMs would count as due diligence, so I go to the Met Office and AIS web sites.
It's all a matter of risk assessment, and each pilot makes his own judgement (cf the common repeated threads on SEP IMC and night flying). Mine is as above. Others will come to different conclusions.