(At the risk of offending some people) I came across this thread/post earlier today in the UCLA forum because I was curious about what the Fiat Lux classes are:
Sorry so long to respond! Actually, the clusters make subsequent registration easier, because you’re guaranteed a spot all year. As a result, you can save the cluster enrollment for your 2nd pass in winter and spring quarters. The only issue is getting the specific discussion section you want, but that’s minor in comparison to having a guaranteed class.
The fiat lux classes had very light workloads – of the four she took, only two had actual assignments (short papers), if I recall correctly.