I have two TTs that came with WFCO converters. Neither one could get into 14.4 volts for fast charging of a depleted battery and neither one got into 13.2 trickle charge mode once fully charged. They both only provided 13.6 volts constantly. This is not ideal for battery life and could eventually lead to premature battery failure. For only a few dollars more, many of us upgraded to the true 4 mode PD charger, which automatically monitors and keeps the battery in good shape using different voltages, and also has an automatic desulfation mode for longer battery life.
I agree that if you only camp with full hookups, the WFCO may function adequately, but if you dry camp, the upgrade is worthwhile.