My wife and I did the Century last year and the climbing coming at the end of the ride is a bit tough on a senior-powered tandem. We're thinking of the metric, the harder of the two shorter rides, but even though the total climbing is less, the climbs themselves look comparable. I'd be interested in hearing from anyone whose either done both or just done the Metric.
BTW, for anyone registered the weather looks to be absolutely perfect. Really looking forward to the ride whichever course we choose.