Four strokes are slightly more difficult to tune, simply because it can't be done by ear. You really need to have a tachometer. Not everyone is comfortable or knowledgeble about four strokes. There's a bit more upkeep involved with a four stroke. You've got to adjust the valves now and then, maybe once a season.

Overall, if you want to start with a four stroke go for it. They're not difficult to handle at all. You'll have to buy a tach and get comfortable using it.