Have performed charge tests of the Iota 55 Iq4 on FWC's 2 group 27's and 24's,  and single 100ah lifeline batteries.  
The one anomaly that some like and some do not is that when the Vbat reaches 14.8 the converter will drop back to 14.2 absorb... I will not get into the detail for now, maybe someone else will.  
As a charging horse race goes against a Progressive Dynamics 9260 they are pretty close at the end of bulk mode, 4hrs for the PD.
Some prefer the PD because of the ability to manually change charge modes.  Nice for cold batteries to get the converter into Bulk mode 14.4.   Also in hot weather... Battery above 95 I like to drop the converter back to Absorb 13.6.... Boiling a battery is bad news.
Good that you are getting rid of the WFCO...
Jim