Google stock does have modifications but not many. It works fine. It is close to AOSP. It's things liek Sense and touchwiz it is not designed for.
Always read the OP's of a thread and the last 2 pages before asking questions, unless there has been an update - in which case, read the last 5 pages!

nexus 5 | SlimKat | ElementalX kernel | Philz Touch Recovery

I do NOT reply to support queries over PM.