4 bucket ebb & flo, drain to tray or pipes?

If I have something like this:


with the buckets sitting on a drain tray, is it common or bad practice to drain the buckets directly onto the table, to then drain into the reservoir? Or is it always a better idea to drain the buckets via pipe or tubing, directly into the reservoir?

With your schematic what I am thinking would be best is to have holes at the bottom of the bucket and have them drain back into the reservoir I have tried this before myself with success. Either way the water has to leave the bucket to get into the rez