Sonic Racing has gone from the game stopping every 5 seconds, making it absolutely unplayable and a shame for the developer to stopping every 30 seconds, making it a crap port from a bad developer (still shame). That's from the demo version. Anyone that played the demo back then can confirm this. The game is crap still.
Off topic, but is there any evidence of faster load times when playing from an SD card than from the cartridge, or the contrary?
I remember on the Wii that games like Xenoblade, when played form the disk where awful, but after ripping and playing from the HDD, was much better.