I'm a mix of the 2nd & 3rd options. I'm sitting at 4 bikes right now. One is my MTB, which serves a different purpose. One is my commuter/beater, which serves a different purpose. Then I have 2 road bikes for no good reason, really. I got a really good deal on a frame and was going to go weight weenie on a build, but I cheaped out and my 2 road bikes are pretty much the same. I suppose it's good to have a backup just in case, but my commuter/beater could have served that purpose.