Raid10 build time is very good, a day or so for 4x 2.5" 1TB disks. i don't have the exact time. I can only compare to an LSI HBA card, which is extremely slow ,weeks of building.
Buying this product on ebay was 2-3 times cheaper as buying it locally in my country, that is when transportation, vat, taxes etc. is included.
I didnt pay attention to the "LOW PROFILE" part, not until it was time to insert the card into the computer :P The computer is not moving around so it is ok.