I have always charged my mobile phones etc. with a simple USB to AC adaptor 

Is it better to use a PD charger or is that just for faster charging

If your device supports fast-charging a compatible smart charger will indeed charge faster.

I'm sure there will be other "advantages" in the sales blurb.

Yes, the charger type will depend on the phone model. Avoid cheap chargers - they will ruin your battery and can be a fire hazard.

Always try to buy the original charger or at least match the specs. As the fast charger 'communicates' with the phone, the phone should have the fast charging capability.

One last important thing is the cable. This too should be compatible with the entire setup. Eg Fast charging cables are different to the non-fast charging cables. Cheap cables can be an eternal head-ache!

Down below are some articles that may help you.

https://www.ideus.com/en/blog/how-to-choose-a-charger-for-your-mobile-phone

https://root-nation.com/en/articles-en/tech-en/en-how-to-choose-a-charger/

Thanks for the advice Guys