I believe the common version comes with the i7-4800MQ later models might have i7-4810MQ, this is the second fastest processor in the Haswell series, might be able to cram a Broadwell chip in there when they come out, but it wouldn't be worth the effort. You probably wouldn't want to pay for the Extreme processor it is about $1000 dollars on its own.
Official spec sheet doesn't say what type of screen it is. Just from a visual inspection I would say it may be IPS.
GPU is upgradeable, but that is no guarantee a GTX880m would work. Firstly there is the TDP to worry about, the included cooler will have a max limit. Find out what the highest card they sell it with is and look at the TDP of that card. That should set your upper limit. Sometimes OEMs stray from standard parts and installing others doesn't always work.
I bought a M4800 for my father to use at home, and we use M6800 at work for engineers on the go. M4800 has a reasonable sized power supply. M6800 is a gigantic flat pack.
Thanks for the reply.
M4800 has higher option for NVIDIA Quadro K2100M gpu with TDP 55w.
But gtx880m has 122w of TDP, way higher that k2100m
What are other points to consider while replacing laptop gpu (connectors, interface etc)
The k2100m has tdp of 55w, does it mean the precision m4800 wont provide higher than 55w to gpu?