I am thinking of buying a T18 + 3 set but can't find the sets with 4.2Ah batteries in Australia (only 2.6 or 3Ah). Does anyone know if they are available/coming to Australia? Are they worth waiting for (extra capacity/runtime-wise) or do they just add more weight? It seems like they may not weigh much more as total weight is listed as 1.75kg with 4.2Ah battery on Festool USA website vs 1.7kg with 3Ah on Festool Australia website??