Simple match mechanics, a simple squad support system, a nice (but small-ish) variety of maps and a great community make this a game worth picking up. It's still in beta, so there are still a few kinks (my issues have ONLY been with the menus, no in-match problems yet @ roughly 6 hours of play). Overall, it doesn't FEEL like a beta, at least not like the ones I've played.

The only thing that is a bit dissapointing is the lack of variety in weaponry. There are 2-3 bolt rifles per side, with unlockable scopes, bayonets and reinforced butts (hehe) depending on which class you play. Some classes like officers can have pistols and binoculars to call in recon or gas/mortar strikes, while flankers can equip rifles or pistols, and are equipped with devastating grenades. There is an LMG class for each side, the German class can only fire while deployed, while the French and British LMG's can be fired while on the move. It would be nice to have some sort of shotgun class (maybe the grenadiers?), but the developers have covered the basic necessities and provided some variety.

Overall, I am highly impressed with this very polished beta, and would recommend it to any of my friends.

EDIT (10/31/15, 210 hrs)
It's a few months after the official release, and this game just keeps getting better and better. The devs are putting out 2-3 updates a month, mostly graphical updates and bug fixes. They've announced a ton of FREE upcoming DLC, and post weekly updates to the community and social media that detail progress being made, and discuss where the future updates are headed.

The player community itself is the best I've ever experienced. Players are (with very few exceptions) helpful, friendly and communicate well. Squad voice chat is useful, and more and more players are using mics and taking advantage of this. Every so often, you'll run across a developer playing in-game and answering questions.

Gameplay has improved, squad mechanics have been smoothed, and a team deathmatch (no trench captures, just killing) has been added. Squad roles and classes ahve been revamped, new weapons have been added: knives, shovels, clubs, and more. With more weapons (BAR, 1911, Springfield, shotgun and a German flamethrower) and new squads (Americans, Belgians) coming soon, this game comtinues to hold my interest.

I'd still highly recommend this game for anyone who loves a good shooter, especially historical ones.

EDIT 11/28/2016
I've nominated this game for the "I thought this game was cool before it won an award" category of the Steam Awards. No matter what shiny new game comes out and piques my interest, sooner or later I always come back to this one for some good ol' fashioned face-sniping, bayonet-charging, trench-capturing fun. Dev support continues to impress. Still entertaining, still beloved, still highly recommended.