I think if you had the opportunity to start riding different bikes to work for variety, you'd never go back. If it were me, I'd get the bike locker.

I have three bikes, and I get up in the morning and head down to the basement to decide which ride I'm taking. Racing on the road bike, cruising on the hybrid, or take the mountain bike and hit some mud in the morning? I love having options.

If I could only ride my crappiest bike every day, I'd be bummed. But then most of my riding is commuting, so your mileage may vary.