The Wahl Groomsman Revolution is an excellent choice for your beard and mustache trimming needs. In six months of ownership, it has done quite well for my needs.
The Groomsman Revolution is slightly more expensive than a Norelco/Phillips or other competitor, but it is a solid product that has lasted well considering it's been knocked off my bathroom counter and hit the hard tile floor more than once.
It comes with five accessories: three different trimming heads, a brush to clean out these heads and a small beard comb for those with longer facial hair. These are pretty normal accessories for most packages, though. The all-purpose trimming head has six settings for length that you can change to, meaning you can go for a minor facial hair look or maintain a thick beard.
The Wahl Groomsman Revolution operates with an internal battery that is recharged. I found that the battery life is good -- lasts for more than a few uses before needing a recharge -- and the ease of use to charge it up is no biggie.
My only complaint is that the heads are made of semi-weak plastic, and you cannot be rough with it (remember though, I've dropped this thing on the floor). However, if you are someone who likes to maintain your facial hair to a certain length and doesn't change heads or head settings a lot, the plastics should hold up.
With the trimming heads, there is much flexibility to get every sort of look.
Lastly, the Wahl Groosman Revolution is one of the few trimmers on the market still Made in the USA, a pleasant surprise for me. The Wahl company has been building hair grooming products in Sterling, Illinois for longer than a lifetime and I'm happy that this trimmer came from my own country.
Overall, the Wahl Groomsman Revolution is a solid offering in beard and mustache maintainence.