$6 iogear GFR209A, corded 12 in 1 USB reader, ASIN:B004QHPYT0
Some ubuntu boxes see- and use it, others pretend it has become existentially challenged.
USB3 devices in USB2 consistently appear to function at USB2 max which makes sense given lazy corporations and foolhardy management which is why to buy USB3 flash USB (UFD)
__Fun with SDcards
$14 transcend TS8GSDHC10U1E, 8gig class10 UHS1, claim 85/22 MB/sASIN:B006LFVJW6 
$14 “sandisk” SDSDX-008G-X46, 8gig Class10 UHS1, claim 30/30 MB/sASIN:B007M54DYA 
Raspberry Pi initially didn’t care for the Transcend 8gig ‘fast’ (a brand ordinary I would avoid) Class 10 UHS-1 TS8GSDHC10U1E claims 85/22 MB/s. ‘Seems’ about as fast as the sandisk 8gig equivalent.
When I didn’t bother with a partition table or partitioning (for one partition) and formatted partitionless Raspberry Pi tolerated (recognized) its existence. Having OpenElec and DarkElec sporadically freeze was a bit tiresome especially Vizio cold booting so transcend provides an Xbian alternative (no such freezes yet). With more patience I’ll try creative NFS openelec. (yes, all shares are NFS, no media SMB here)
The Transcend 2 gig TS2GSDC I bought for an OOOLLD camera I haven’t tried feeding RPi. $4.99 ASIN:B000FGNM6I
no RPi issues gut feeling clone. Had a ‘great’ time with amazon CS trying to find the correct ASIN for the retail part: their FFP/retail selector would only add ‘FF’P to the cart. Sandisk says they don’t package for amazon which means a lunkhead opens the static sensitive bits to repackage (or a robot with lazy maintenance/programmer). I routinely receive non-electronics pick-robot packaged like fine china but delicate electronics with nothing more than a packing slip inside a skin tight box. fabulous! I can return until they do it right.. how much double-shipping loss is amazon willing to absorb before ‘someone’ steps in to correct glaring errors? I miss the foldable sandisk combo USB plugs. The 512meg version I have is only suited for BerryBoot