Yep, I get the lag now and then, especially right after starting the car but also at some random intervals. One thing I did as a stopgap to speed up loading is disable the auto contact sync for my phone on every start. Seems to quicken the load process. I've found that if it doesn't respond right away, let it do its thing. Hitting it again before it responds - not good.
On another note, I got a new one this morning. Took me a minute to figure out but I knew something about the screen was strange in my peripheral vision. Upon closer inspection - no temp! Things looked really off-balance with the time over on the left and blank space to the right.