Transfer speeds

Okay so huge thank you for the support so far and making this out there.

Have mine all set up

Pi V2 512MB built by Sony in Pencode Wales
32GB SD CLASS 10
9000mAh Portable Power Bank [www.maplin.co.uk]

Have a 1.4GB file on there.

The transfer start off around 1.5Mb/s then drops to a slow 233kb/s

Any ideas?

Is it faster to transfer to a USB HDD or decent USB FLASH stick than a class 10 SD card?