I've got MH4U and Super Mystery Dungeon. Both are AMAZING games, and both require a lot of time. However, even as a big PMD fan, I find myself playing MH4U much more often. This is because its just so much fun and engaging. It's also very addictive. Prepare to spend hours by yourself or with other taking down massive dragons to get that *one* last scale to complete an axe that turns into a sword and shoots out lightning. If you're not prepared to spend a lot of time and effort, it's not for you. It's very rewarding, but PMD might be better for you depending on your position.