Ok so here it goes-

Which one you use?
which is better?
what is your response?
which one is prone to problems?

thanks

note from Hobby King :We strongly recommend customers to select (Registered) over regular Air Mail.
HobbyKing.com accepts no liability for unreceived 'Air Mail' parcels sent without registration.

I use registered air mail..Happy with it..

Me too.
Once i mistakenly ordered a part through unregistered airmail,Thank god! it delivered safely.

FYI, Airparcel took 32 days for me

I think the Poll itself has wrong practical Data (should not be the one shown on HK Site)

I would fathom if any one in India get the Air mail/Parcel in 6 days!!! best case is 12-14 days of ordering (what mushy mushy happens between HC and HK post is still unclear).

In my experience, Air Mail is better, reason being the trip timing from Order to reaching your Local FPO is same. It is for how long Customs holds the package matters the most.They are usually lenient with Air Mail, and hold Air Parcel most of the time. Whatsoever,  the average time for both Air Mail/Parcel is around 3 weeks from order.
Getting something huge, risky (Tx) ,declaring a ridiculous amount etc would definitely result in longer wait time.

But any day, I would prefer a registered Envelope - not a box parcel. They have amazingly < 10 days turnabout time!! 

any failure or customs penalty from anybody when ordering from hk