Hello, there are a few things going on with hammerhead and Maru 0.6 / Android 8 that are relevant:
1. Some of our legacy devices like the Nexus 5 don't have enough space on their system partition to ship the desktop image so we had to disable Dex preoptimization which can make the first few boots slow while Android compiles all of the code for the apps shipped by default on the device. If you install Google apps on top it can get even slower since the device has to compile all of the Play libraries.
2. Android 8 is known to be sluggish on the N5 versus Android 6 and 7.
We are working on improving this situation with our next major release based on Android 9.
Hope this helps and thanks for using Maru!
Best,
Preetam