I've been using Sager since 2011.
I have "my old laptop", the 2011.
"My new laptop", a 2015. I got when the graphics card acted up. Baking the card did get it back into operation. It did eventually die again and I just recently replaced it with a new card.
The main thing I learned there is do your research and find out what cards will work with your laptop. There may also need to be a particular vBIOS on the card to work properly.
The 2015 is still going strong.
I also have a work Sager, also 2015 I think. This is the lightest one, the others definitely fall into the "desktop replacement" category.
Since I don't really move them much I started shifting back to tower computers for the easier upgrade path. I don't need to lock myself into a laptop, so I never needed to go that path, but Sager's are a solid platform.
Always load the HotKey software driver. Plugging in a headphone might act strange if you don't.
On the new one Linux uses the SPDIF audio jack for headphones, Windows uses the regular headphone jack.
These are the tidbits I've learned over time. All brands have their little gotchas.