Just finished the Adeptus Mechanicus books by Rob Sanders, don't recommend. Unlike Abnett's god tier Titanicus or the HH Mechanicum the book felt pointless. I wasn't expecting some earth shattering revalations but it's just two consecutive parts which are sequences of battles (there is literally one character in each book) and shilling the new faction toys. There is no character developemnt or an interesting outlook over the mechanicus as an ideology and how it diverges from the the Imperium.
Also the main driving force around the plot is some anti warp weapon which can horrifically backfire and the book describes it as too dangerous to have around, which is slightly bullshit considering it's shortcoming can be worked around (though I guess on the other hand having the traitor legions use it is insanely dangerous, which is another plot hole).