I havent built any F/A-18Es, but since your question has reference to the brand, well, lets see.
Italeri carries kits originally made by other brands, such as Zvezda, Dragon, and ESCI. Conversely, some Italeri kits are or have been marketed by other manufacturers. The Tamiya 72nd line is an example (although not all are Italeri kits). So its hard to tell you exactly what to expect. I'll proceed with Italeri originals.
The plastic is generally softer than what youd find in a Monogram, Hasegawa or Academy, so take it easy on the sanding. The details are okay, but the engraving on some samples are just a bit on the heavy side. Canopies are usually thin, which is great if you pose them in the open position.
So far I have noticed two decal suppliers for Italeri: Cartograph and Zanchetti. Cartograph decals are a little thick which makes for difficulty in trying to get them to conform to contours, and have adhesion issues. Zanchetti is far better, and usually has little or no silvering.
Hope this helps.