Some have gotten UEFI to work, but it varies greatly by Vendor and model. The high end models are often UltraBooks that add in complications of RAID with Intel SRT and dual Video or needing bumblebee. This is not really a Linux issue, but vendors not supporting anything but Windows. And it is so much change that the reverse-engineering required to implement all the new drivers and configurations to work well in Linux is very time consumming. It will be a year or two before Linux really catches up with all the changes.
If you really want a high end system, I also recommend a Desktop and build it your self. You may not save much money, but get better components.
I find my laptop not very ergonomic and have issues when using it for longer periods when I travel. And I set it up identically to desktop and just use rsync to copy all data to it when I leave and copy all data back when I return. Some use a new fangled thing called the cloud to do the same, but I do not fully trust clouds.