It could depend on your beard length.
For many years I used a Wahl plug-in trimmer. It's actually quite good, never drains its batteries, and has a number of useful attachments. But: it doesn't have a nose hair attachment. Bummer.
A couple years ago I also got a Philips/Norelco - different from the one pictured in this thread - and it does quite well on shorter beards. Plus the nose hair trimmer, works great. Well, as good as any nose hair trimmer. It's also water proof.
Over a year ago I started growing out my beard to the point where neither the Wahl or Norelco could handle it. I actually trimmed my long beard at one point with a Flowbee. Actually worked fairly well, although stiffer beard hairs and the Flowbee don't get along all that well.
About a month ago I got tired of the beard dipping into the soup and trimmed it back with the Wahl. Left the mustache long, though. Found a good mustache wax.
Might have to go back to the Flowbee.