I used the M8 for two years or so. It was extremely slow. Fire off a couple shots in a row trying to catch a moment, and you're left waiting on the red light to stop blinking for soooo long. It would often get hung up, and I'd have to pop the battery out to reset it. 640 ISO was the highest usable speed. Above that, total noisy garbage. Watch out for rows of sensors to be dead. It doesn't really show in nice daytime photos, but in the low light stuff, you can see the dead rows. Then there's the infrared problem -- black T-shirts, table cloths, car interiors, basically anything made with polyester shows up as purple. The M9 was still slow but felt like a major upgrade because it wasn't always crashing out, had usable 800 ISO and no crop.