I've tried this out on a few different areas and my biggest complaint would be that when the areas are curved it can be difficult to get a really close shave (for example, the eyebrows), but electric trimmers never seem to cut as close as manual razors do and it can be quite hard to get a manual razor at the eyebrows.
On the opposite end of the scale, it does an amazing job at trimming upper lip hair. My upper lip hair isn't particularly thick and is usually blonde, but shows up darker in the light so I prefer to trim it and find this does the job much more easily than my husband's electric razor, which is obviously made for heavy beard hair.
I did find the attachments to be mostly pointless, but it really depends what you're using it for. One thing I noticed is that it has a tendency to gunk up on the blades, even when rinsing it after use. I found the best way to clean it is with an old soft bristled toothbrush and a gentle scrub before rinsing.