I'll jump in here... the MB people recommend the 160 setting and that's all I've used with the 2 hour setting. Both my batches came out great! I used 1lb of butter and 1/2 oz of herb both times. it may have been a bit under the minimum line but i didn't add any water. First time I used popcorn buds and the second time was manicure trim of the same top shelf strain. The buds were maybe 15% more potent. I did not use lecithin for either batch.
The butter came out light green and was very effective. I made 32 cookies per batch of butter. Each cookie was good for two light but really fun doses which is what we prefer. A whole cookie had impact on a non-stop smoker friend though he felt it could have been a bit stronger.
So to summarize I would stick with the 160 temp, add more herb and maybe not add more butter.
Oh, the sludge that was left in the bottom of the filter was very tasty to me. Instead of tossing it I would recommend adding it to some spaghetti or eating it straight. It looked gross but really wasn't. I haven't done either but it was tempting... but I have cookies so I ate them instead.