The range of XPS laptops are fantastic, in particular the 9560 but also the slightly older 9550 if you're looking to save money.
Depending what you're intending on using it for, stick to the FHD 1920 x 1080 version if you're looking to game. Gaming on these 9560's with the 1050 graphics card is possible but only at medium to high settings for smooth game play. The older 9550 with the 960M graphics cards are also capable but bear in mind that it's a good 20-30% slower in gaming when compared to the 1050 (don't get this confused with the 1050ti, this is a more powerful card but really only featured in more expensive laptops - have a read up on the comparisons between the 1050 & the 1050ti).
In my opinion only go for the UHD version if you're not gaming and say can make use of the 4K resolution wisely, you can do pretty much anything else with it but the larger resolution for gaming is wasted due to how demanding 4K is and the fact that these laptops simply do not have the capacity for 4K gaming. I remember from reading, Dell released these laptops with 4K screens to target the video editing market.
Speaking from having briefly owned both the 9550 FHD & 9550 UHD versions in the past - I think if I could pick again, I would choose the FHD version. The reason being is that I feel I would make use of the FHD screen better when compared to the UHD screen, as I do tend to game very occasionally. However... the UHD screen really is out of this world, and quite possibly the best laptop screen I've ever used by far. Nothing else comes close to it. However battery life is better on the FHD version too.
If you're still looking into getting one, get one that is complete with the 512GB SSD drive - as it'll come with the bigger 97WHr battery. The more budget version with say the 1TB HDD / 256GB SSD will come with the smaller 56WHr battery (this is so it can accommodate the mechanical HDD).
Lastly, be sure to take a look at the Dell Outlet deals online where you can get nearly new refurbished units for up to 2/3 of the price of a new one. You'll save even more going down this channel too.
Liam.