I have used both Kingston and Microcenter USB flash drives. But I have a full install in my 16GB Kingston and it run 12.04 now.
Some have had issues with different flash drives and the different flash drive installers.
Pendrive also has page on booting ISOs
fred@fred-LT-A105:~$ sudo parted /dev/sdb unit s print
Model: Kingston DataTraveler 2.0 (scsi)
Disk /dev/sdb: 31375360s
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 2048s 4095s 2048s KingstonData bios_grub
2 4096s 14749695s 14745600s ext4
3 14749696s 29327359s 14577664s ext4
4 29327360s 31373311s 2045952s ntfs
I actually now only use grub2's boot loader to directly loop mount ISOs for installing either from a hard drive or flash drive.