Hello, Please understand the difference between the P series and the U series processor.
U means "ultra-low-power," basically they're chips based on low-power designs made with efficiency in mind. They have lower clock speeds, fewer cores, and more importantly, a very low Thermal Design Power.
P processors sip a little more power—28W, to be precise. That's almost twice. As such, power and thermal requirements for these chips are higher, and you'll need beefier cooling. Also, you will get twice the power in this processor as it will have more cores and threads.
So for day-to-day work 1255U processor is good. But if you want something extra then go with the 1240P process which is great and will cost you a little less.