Nope and nope here. I admit we don't use 2.4Ghz much here and the signal is good throughout with an AC87 router and a 2nd acting as AP, but no problems at all and InSSIDer, for sure shows the same signal strength.
5Ghz working well here with 12 13 days of uptime since I was messing around after installing 4950. Currently getting 400mb/s actual file transfer rate between laptop and wired PC - as good as it was day one.