If you are going Dell I think the best bet is to try the Precision 5000 series (pretty equal to XPS 15) and 7000 series (heavier and bulkier but you can really spec these things out). I have an XPS 15 (9550) and I really cannot recommend them. Lots of problems.
At least the Precision line is the buisness line which means better support, preinstalled with Linux (so its tested well) and probably from what I have read better tested/built due to being a business line. I like supporting Dell on this venture b/c they are sticking thier neck out a little by even supporting/preinstalling Linux as a big name OEM provider.
The Lenovos are great too, but I wish they would officially support Linux and offer Linux preinstalled as an option so you don't have to pay for Windows.
Both the Precision 5510 and the M3800 I used to have, had issues with the battery swelling. The M3800 was a piece of junk - pretty much what I'd expect when a company that makes $300 laptops uses the same design team to make a $3000 laptop. The 5510 felt much better, but the screen has a bit of discoloration at some of the edges, and while the keyboard is great, the trackpad isn't that good. The speakers are hilariously bad.
The 5510 is a lot more rigid than the 3800 was, but it still isn't rigid enough. I could carry my personal 15" macbook pro all day with one hand while still being able to click the trackpad down. With that 5510, the chassis flexes too much for the trackpad to click when you hold it from one side. And don't get me started about the cheesy chargers Dell uses.
The 5510 was worlds better, I'll admit - and it does a decent enough job running Ubuntu! There's enough to like about the laptop, but not necessarily at the price they charge.
My work laptop is an M3800, though the newer one is the 5510. Pretty solid machines in my experience. We did after market upgrades to some very fast SSD (sorry don't remember which).
That said- I'm staying with the m3800 as long as I can. It's a few years old and my battery needs replacing, but otherwise is very capable. Some people have had docking issues on and off with the 5510 (occasional crashing, though I think it's a driver/software issue), but more importantly it has the awful "Nostril Cam" which is annoying for video meetings.
In general, fast, light, good battery (for perspective, mine lasts 2-3 hours now, vs 5-7 when I got it), useful ports. The keyboard is not the best (home/end/pgup/pgdn keys are fn+arrow instead of dedicated) but very usable. I hated the glossy screen at first, but touchscreen is surprisingly useful and I got past it. I just keep a microfiber cloth in my laptop bag now.
yeah "up the nose" cam is one of the more annoying features of these Dells :( Also the non-dedicated pgup/dwn/home/end is another annoyance - I guess I got use to it after a while
Thanks, I won't be actively looking for 6 months or so. I'm just keeping an eye on what's available. Precisions are prohibitively expensive here (Aus) -- starting at about AUD$6000! Thinkpads raise a nostalgic smile. My little x40 with dock was probably my favourite ever machine.
At least the Precision line is the buisness line which means better support, preinstalled with Linux (so its tested well) and probably from what I have read better tested/built due to being a business line. I like supporting Dell on this venture b/c they are sticking thier neck out a little by even supporting/preinstalling Linux as a big name OEM provider.
The Lenovos are great too, but I wish they would officially support Linux and offer Linux preinstalled as an option so you don't have to pay for Windows.