I routinely play in my own games, often because the party could use one more member, or just because there's a character I want to play. To me, playing a PC is not much different from playing an NPC. Since I have all the inside knowledge, the key is to make sure my character is not the one making the decisions, so usually I make them someone who is not very bright, or is just very action-oriented, or whatever. The only thing I don't like is occasionally when my character has to interact with an NPC, which is then me talking to myself. So I make sure my character is not the face of the party, as well as not being a decision maker.
In my current home game, I also find it useful to have a party member (mine) that can get into trouble and need to be bailed out by the rest of the party. So there are good chunks of time when they are out of the action and working more as a plot device.
I enjoy playing in my own scenarios. I run very sandbox-style games, so a lot of the story is emergent, and getting to experience it along with the other players is great fun. And I create very elaborate sets using all of my hand-painted terrain and miniatures, accumulated over many, many years, so it is extra fun to feel like I am right in there.