The NEX 7 on RAW+JPEG will buffer at 9FPS for about 15 frames and then slow down. Remember that these are 24MP files so the raw files can be 60MB+. The high end Sony memory sticks are much faster than a Class 10 SD card but they can only do so much....
Yup you are right. I also realized this. Everything is a balance. Cameras which have too large files, cannot shoot too fast or if can shoot fast, cannot shoot too long. Haha. That is why, the E-M5, is quite impressive. Even at RAW+JPEG (at Large Superfine mode), can still shoot at 9.5 FPS with no apparent end in sight. You all should go and try it. End up shooting so many that after you stop shooting, the card is writing for about 10-15 seconds after you stop.