iPhone 6 Plus - Severe Lag

I have been using the iPhone 6 Plus since launch and I have been plagued by severe lag. For instance, the phone completely freezes when getting an incoming text message and the notification shade comes onto the screen. Also, when switching from one app to another or trying to type at a "normal" speed there is a ton of lag, has anyone else noticed this? I have never had any issues with previous iPhones and I feel that there is an issue since this phone is reported to be "fast". Even writing this post the phone has lagged several times. Any insight of assistance would be greatly appreciated.