I finally got my hands on the conifer forest pack, and it is absolutely fantastic. It looks even better than the screenshots Willi posted, especially on a 5k monitor. As for the performance, I achieved a stable 20fps at 4k resolution on an iMac (8gb ram, AMD Radeon R9 M380). Just in case anybody is wondering, I got about the same performance with this pack as I did with Landscape Auto Material. I even get great performance on my laptop (8gb ram, GTX 960M).
Willi, I can’t wait to purchase your future packs, and I highly recommend that everybody buys this. Well worth the price.