Flash memory or SD card that you mentioned would be safer, as ALL and any hard drives can crash losing saved files. There are no moving parts in a flash / memory card camera. Hence more efficient also.
I'm sure either would be fine for you, SD cards are getting cheaper by the day, but flash memory is safer.
Check other forum's i asked the same question when i sold my Sony HC3 dv tape machine, There are many who have had problems with hard drive cameras crashing.
I'm actually sure its rare, but it can, and DOES happen.
JMO
Jon.
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