Construction is very straight-forward with only minor problems. The assembling sequence starts with the assembly of the propulsion bay, but I think it is better to start with the central core and boosters and not to glue the bottom part to the central core until the first stage has been painted. All halves fit quite well but some sanding is required which destroys some of the recessed panel lines. These were rescribed later. The holes in the boosters in which the pegs of the base are supposed to fit in need to be enlarged, do this before the boosters are glued to the main core. The hold down posts of the propulsion bay didn't quite match the recessed area on the boosters, so I slightly rotated the boosters which hides the small gap.
The painting instructions are very clear, but only Humbrol colours are mentioned. They are generally available in France, but I doubt if they are in the rest of the world. The boosters and central core main colour is gloss white: for this I used an acrylic spray can. The lower half of the central core is shown as a brick pattern, the bricks being matt pale stone and the spacings a lighter colour. As I haven't seen any pictures of a real Ariane 5 yet, just the battle stage and the mock-up at Le Bourget '95, I painted this all matt pale stone. After this dried the propulsion bay was glued to the central core and paint blemishes were touched up with a brush. I covered the bands on the boosters with chrome foil 2 millimeters wide. It's not in the instructions, but I liked the look of it and the mockup at Le Bourget had them.
The built model looks nice and gives a fair representation of the Ariane 5 as it has appeared so far. Construction took 5 hours, not counting the time to let the paint dry. The price is a little on the high side for an injection molded plastic kit in the rather odd scale of 1/125. I ordered it directly from the manufacturer, but Squadron Mail Order also sells the kit for a whopping $59.95.