I have the O/14-54 Mk2 and the m.43 L/12-35/2.8.
The 12mm extension on the wide end is ......addictive

And absolutely useful. Can't imagine how I lived without 24mm ....... On the other end, the 54 (108 equivalent) is absolutely fantastic for portraitures .... 35 (70 equi) is crappy ......
Anyway since getting the 12-35/2.8, the 14-54/2.8-3.5 has stayed in the box ..... I think the 12-35 is sharper, better contrast, better bokeh and better distortion characteristics than the 14-54. The 14-54 wins at portraiture.
Both are weather resistant. 12-35/2.8 is overpriced compared to 14-54/2.8-3.5, more than doubled. The 14-54 is also double the 12-35 size and feels hardier. The 12-35/2.8 handles beautifully, makes for great pictures and is worth its price though, i.e. the 14-54 is a BARGAIN.
Wished the 12-35 was 12-45/2.8 though ......