I just got in the post a WW1 Infantry Brigade in 1/600 scale from Tumbling Dice, and I would like to share some photos and a description.

First of all, the service was excellent (I got the miniatures in a few days from UK to Continental Europe) and I received a list of all their 1/600 range of aircraft and land subjects, too.
The pack is made of 16 strips of infantry in close order, 16 strips of infantry in open order (each with 8 men), plus...
... 2 supply carts and 2 wagons with horses, 8 strips of supply weapons, 6 guns (you should specify if British, German or Russian when ordering... these are British 18pdr guns), 3 limbers with horses and mounted crews, 8 strips of cavalry.
Infantry are all standing, wear a peaked cap and have a backpack, making them suitable for early WW1 British, or Russian, or other later XIX - early XX century troops. Bases are 20mm wide for close order and 30mm wide for open order infantry. The little guys are 4mm tall from feet to eye (so to say), and this makes me think that they are bigger than 1/600 scale... if 1/300 is 6mm. 
Guns, limbers and horses are nice, only the men sitting on the limbers are much smaller than their colleagues. 
The wagons have again smaller men. Support weapons strips provide a variety of MGs, with shield and wheels or not, mortars and groups of men carrying something... I think they are ammo boxes.
Cavalry is proportionated to infantry and well sculpted, considered the microscopical scale. Riders wear a shako.

I plan to use these miniatures for 1904-05 Russian and Japanese, and/or the Russian Civil War, using the Pz8 WW1 Divisional Rules...  how they will look when painted and based? I will let you know...