Like Paul says, it really comes down to what you are designing.
For the most part, I prioritize wall thickness over infill, as it normally yields a stronger part.
Some things like fin cans, I'll create the model so the actual can is 1.5 mm thick, or 3 full walls. However, I'll design my fins to be 3 mm thick at the root. Settings for perimeter count will be set to a really high number that results in the fin being nearly 100% plastic due to these settings. This results in a much stronger fin than relying on infill percentage. I do the same thing with nosecones, and many other parts.
For most LPR we use 1.25mm wall thickness. The slicer is set the 3 walls provided your printer has a 0.4mm nozzle. This will provide the best tradeoff between strength and weight.. It just seems a two perimeter wall thickness with a .4mm nozzle does not have the layer strength needed, at least in ABS. Another tip is to set the heatbed at 100c to 110c for ABS and set the hotend to the highest temp that will still produce quality parts. For us that's 255c.................