I bought the "Green Gustav" as a complement to a Brio train set, which includes the already two "Speedy" locomotives (Brio 33222). The Speedy locomotive which is equipped with only one AAA battery, unfortunately, is very slow and can not move, what the gameplay my kids braked a bit longer trains. Therefore a stronger locomotive was needed. The "Green Gustav" fulfills these expectations primarily. The locomotive is equipped with two AAA batteries and is significantly faster and stronger than the Speedy. Longer trains can be easily unplugged in any case with full batteries. After some time, the power can then but noticeably. Since the power is transmitted only by a pair of tires, also the Green Gustav has traction problems here and there. Especially on slopes, on bridges or in very tight curves, it may happen that the locomotive does not provide sufficient grip and something has to be pushed, because the drive wheels from spinning. This affects the gameplay of children but not significantly, and compared to the small and weaker locomotives Green Gustav is definitely a big gain in enthusiasm. Too bad that is not the bigger AA batteries can be used. Perhaps the locomotive would then run out of steam a little slower. The quality of workmanship is good and the design robust.