I'll stick with the 35-100. A big reason I switched from my FF DSLR gear was to go smaller, and the 35-100 is a perfect example of that being about half the size and less than half the weight of the 40-150. For me personally, 35-100 is a good range for a standard tele zoom, great for general purpose use and travel. While the 40-150mm range sounds nice, I would still need a long lens like my 75-300, even with the 1.4x that only gets you out to 210mm, while for wildlife I find 300mm can be a bit short and often crop further. Also, I can carry both the 35-100 and 75-300 which add up to slightly less weight than the 40-150 alone.
I'm sure others will have varied opinions, but for me the size of the 35-100 is just right while the 40-150 is simply too big. It would sit on my shelf at home more often than not just like my Sigma 70-200/2.8 did, so no matter how excellent the image quality is, it's simply not a good choice for me.
This is also not a range I shoot in a great deal, I generally favor 7-45mm range or so, so having a large and heavy (even if excellent) lens for a small percentage of the shots I take doesn't make much sense. The 35-100 is small and light enough that I can throw it in a bag and only use it a few times without feeling like a fool for hauling around a big lens that I barely use, and I often felt that way with the 70-200/2.8.
... I had the P100-300 and I got *some* good results out of it, but I fund myself struggling with the A/F and missing a lot of shots.. This could be my lack of skill, but I think it could be improved by a faster, better lens. The 50-200 also suffered from A/F issues with the E-M5. The E-M1 was much better for the 50-200, but in the end I decided to sell it and but the new 40-150.....