Well let me ask you this, if the filter does crap out on me how long will it take for the tank to reach a dangerous state? I don't think it'll happen in 8 hours. Then again I have no real experience with it.
If the worst happens while I'm at work my wife gives me a call and I stop by petsmart on the way home to buy media for the power filter. She tosses the biowheels in the tank to keep the colonies alive and when I get home I stuff the old filter cartridges from the bio into the power filter and get going. It won't be pretty but it'll keep my fish alive until I get a replacement and the colonies grow into the power filter's media.
Ideally I'd prefer to have a brand new filter, there's an element of risk here because I have no idea what happened to these things before I got them. I just think the risk is manageable right now since I have a second full sized filter to fall back on if I have to. Believe me, if I didn't have the second filter I'd be replacing the Penguin as soon as I had the cash saved up.