Plenty of reasons why it can't completely replace your laptop.
Throttling (and heating) is one of the main reasons. Unless you're a very light user, you will experience throttling issues. Average users also play games on their laptop (I don't mean tetris) and this is another thing SP3 can't do without throttling.
It even throttled when I was watching a movie on chrome while installing a light program.
There are also other minor reasons like it doesn't come with a keyboard, it only has 1 USB port, etc. which definitely all add up.
Given the budget, it makes sense for one to go for a proper laptop than an SP3 if he/she doesn't already own a laptop.
SP3 is great as a laptop supplement, but to be a main laptop, it's just not there yet.
false. i know many who have replaced their laptop with a sp3.