The feel of the Power Cover is the same as the Type Cover 2. It is exactly the same type of cover with the exact same keyboard. The layout and size of the keys are the same as well. The one thing missing, but not a deal breaker, is that the keys are not backlit. In addition, it is about twice as thick and heavy as the Type Cover 2. It adds weight to the Surface Pro, increasing the total weight to about three pounds. The weight is still lighter than most laptops if not comparable.
The Power Cover recharges your Surface's battery while in use. One thing to note is that when connected to your Surface device, power is provided by the Power Cover battery first, before utilizing the Surface's internal battery. Also, when you charge your Surface with the Power Cover connected, the internal battery charges before the Power Cover starts to charge.
Yes, it's thicker than the other Surface covers, but it's definitely easier to carry around than the power supply or some other additional power source. As someone who has spent up to $200 for replacement batteries for laptops in the past, this is an accessory that makes sense if the Surface is your primary, on-the-go computing device.