We had a guy on our project using one of these a few months back to cut roofing insulation battening as well as some 3x2 CLS framing. He seemed to do OK with it although he was using the bigger 5Ah batteries and he did say the saws were sensitive to blade sharpness (they use extremely thin sppecial blades in the same way that cordless rop saws do). I didn't seem to bog down particularly on that sort of gear.
It may be worth stating that I've framed out entire floors of buildings in 3 x 2 and 4 x 2 softwood using just a speed square and a Makita 18 volt cordless (brushless) rip saw - and the same applies, namely your blades must be sharp, they must be the ultra thin ones made for cordless saws (and BTW the DW ones run rings round Makita, Dart and Trend products) and you need one or possibly two 5Ah batteries to run for a day on a fresh 24t blade. Did similar work in the past with the brushed version of the saw and that was deffo 3 x 3Ah or more in a long day. Of course if you are using other tools on the same battery system it's less of a push