All ,of the ICM kits are excellent, and generally regarded as the best Spit kits, certainly in this scale, and, until the Tamiya 1/32nd scale kits arrived, in any scale.
However, they can be a bit tricky to assemble, mainly around the nose, and the wing to fuselage fit. I think they were designed to be built with either the engine displayed, using the separate cowlings as diorama 'dressing', or omitting the engine if cowlings closed.
They take a bit of work, but nothing too difficult - have a look at my thread and Crimea River's thread in the Commonwealth Group Builds, where you will see what is required on the MkIX and MkVIII, both basically the same kit. The low back MkXVI is the same, apart from the fuselage of course.