Not really a fan of the all white icons in notification bar now. I haven't had any wifi issues since the update as some are speculating calls for a reset of phone to clear up.
Have noticed some SMS issues since update, a couple of messages just sort of hung there saying they were sending. One came back that it didn't go but as I was about to resend it, the recipient replied to the message so I know he got it. Has been a few since then to various people that seemed to take longer than normal to send (averaging about 20-30 seconds) before I get the timestamp indicating to me it was sent. This has only been a couple messages, several hundred other messages have been fine, I just have not had texting issues with this phone like this before.
Also, could just be the phone/app but I have HORRIBLE lag with SwiftKey. I think it has been getting worse and could just be in my head that it got even worse after update this morning. I was trying to tap suggestions while typing and the lag was so bad that a simple tap of a suggestion would result in it thinking I had pressed it several times and was asking me if I wanted to not suggest XX word again. Typing a simple sentence took minutes with flow and touch typing.
It's funny...the lag in Swiftkey was something KitKat actually fixed for me.