Ranked in these QuestionsQuestion Ranking
Pro Relatively cheaper high end ThinkPad model
For an i7 machine, this is the relatively cheaper ThinkPad model, especially when you can replace parts yourself.
Pro Good keyboard and touchpad
The keyboard is very comfortable and great for programming.
Pro Expandable RAM and storage
You can replace the RAM and the SSD or HDD yourself, something most ultrabooks no longer offer.
Pro Manufacturer option for battery expansion
The P50s has front and rear battery slots, with three options for the rear battery to make the weight-vs.-battery-life trade-off customizable.
Pro 6th-Gen Intel CPU
At minimum, the ThinkPad P50s comes with a 3.0GHz Intel Core i5-6300U processor. Configurations are available up to 3.4GHz Core i7-6600U.
Con Not for non-developers
If you are not a developer, this laptop does not have any fancy features. It is not slim, nor it is very light. There is no USB C or Thunderbolt, the graphics card is not great for gaming either, though it works well for Photoshop. Overall it's a very dependable laptop meant to be a workstation, it just isn't as portable or flashy as many Ultrabooks.
Con Long assembly time
Regardless of configuration, Lenovo gives an estimate of 5 to 7 days before a new laptop is shipped.
Con Mandatory Windows 10 license
There are no alternative OS options, or no-OS configuration. You're stuck paying for this license whether you need it or not.