I bought this because my daughter has one ... although hers goes much louder than mine I am happy with it. Still could go louder I do not know why they limited the volume on the new ones.
This has turned out to be indispensable in getting our baby to sleep, and for longer periods of time. I haven't used others, or done much research, but this one works great. Compact size is useful in a one bedroom apt and for being able to help him nap on the go.
We got this versus the baby version because others said it was essentially the same machine. I wouldn't know that for sure since we only have this but it is certainly getting the job done. Plus we just needed a little something for the baby while we were traveling. When we turned it on, I swear I wanted to go right to sleep! The noise we chose emits such a deep, soothing sound for such a small machine. We use it every night instead of baby's other machine now since it stays on all night & it's a great sound. Kind of a weird feature, but when it is plugged in and charging, you can't turn it on. It's not terribly inconvenient to unplug, turn on, and plug back in but I thought it was weird. We keep it plugged in consistently since it is baby's main noise machine.