MSI vs Dell vs Lenovo?

Personally id go with Lenovo. To me they have generally better build quality. Also i had a dell laptop die in flames for me so yah… Just a bad experience lol. I don't know much about msi's offerings.

I'm in love with my current Lenovo Laptop <3

You have to get into specific models and customizing.
Are you looking for a gaming graphics card or a CAD software optimized card?
Are you prepared to get Windows Professional or Ultimate rather than Home versions?

You need to bring it down to specific models and not brands.
Here are the Thinkpad Workstations:
http://www3.lenovo.com/...rkstations

These are the Dell Precision Workstations
http://www.dell.com/...on-laptops

And, MSI
https://us.msi.com/Workstations/

Show three complete specified models and then they can be compared.

If not a true workstation laptop, then show what you have in mind.
It's less about brands and more in what goes in each.
Lenovo Thinkpad Keyboard is the best of the three.
Lenovo Thinkpad tends to be the most rugged.

Which ever has the best spec

I would never buy a Dell but that is a personal problem. I have an MSI GP72VR 7RFX Leopard Pro. Paid $1500. Screwed up. I got the 500GB SSD only model. You can get one with 500GB SSD and 1 TB HDD which is better. I put another 500 GB SSD in it. I had it hanging around and said, what the heck. YOU WANT an SSD to have OS on. Believe me, you do! I have been converted so much so that I put a Samsung 960 Pro 512 GB M.2 SSD on my latest build. The boot times are miraculous. This one has a 120HZ screen display which is very nice and 17.3" which seems like better for CAD. HP is now making Omen models that you might look into also. I have an HP Envy and it is about as good as the MSI and was 600 bucks cheaper on sale. No SSD though. But the Omens do have them and better screens. The specs look good. I would look at both the HP Omen and MSI Leopards and see which you like. They are VR READY which means you could CAD in VR, I would imagine, wow!