For about 2 years, I've been using Link2SD (root required) on my (outdated 600MHz ARMv6) LG Optimus S in order to run my apps (to the extent possible) from an EXT4 partition on my Class-10 32GB SD card. All of my SD-card-based apps work just as well from SD card as they did from internal memory-- including my performance-sensitive media streaming apps, e.g. SprintTV, WatchESPN, DishAnywhere (video streaming), Pandora, XiiaLive (music streaming), & GrooveIP (voice-over-WiFi).