A friend got her son a Lenovo for Christmas and I had the pleasure of setting it up for them.
A couple of issues to think about:
1) If you don't move the laptop about the house much (i.e. you normally work at a desk) is it feasible to connect to the internet using a cable rather than wifi? It obviously depends where the internet router is in relation to your desk though. One other option is to use plug-in adaptors which use the mains wiring in the house to transmit the internet connection direct to your PC.
Wifi is great if you move around a lot or the device doesn't have an network adaptor built in, but physical cable links are almost always faster than sending your data through thin air!
2) Windows 10 itself is fairly demanding on your internet connection, regardless of what you are trying to do yourself. Updates and live tiles have already been mentioned, but if you know what you are doing or are willing to find out, it is possible to identify and deal with many other sources of loading on your network connection. One of the early issues people raised about Windows 10 was that as well as your device having to update itself, MS had arranged things so that user's devices could also be the source of update files for other users. So in theory your neighbour's Windows 10 could be updating itself using files from your laptop, not the MS website. Obviously on a slow internet connection this could be a problem - and luckily there was an option (again if you go looking for it) to stop Microsoft from using your device as a 'free' fileserver

One other tip - if you don't already have a 'btinternet' email address (provided 'free' with BT Infinity) you should think twice before switching your current email address to a BT one. If you ever leave BT they charge a fee, currently £5 per month, to keep your old email address going.
