Dell's support is second to none (but on par with HP) ..lol
The Precision is what you might consider if you make it to 2nd year (I know I know.. we're all geniuses) because its very expensive but is purpose built to handle CAD and the high end rendering needed for engineering and other sciences. In first year there's more than enough capacity for an Inspiron to handle it.
Sony and Acer do not have next business day onsite repair capabilty - something you only appreciate when you get a lovely blue screen or something else happens. Lenovo is a carry in warranty. Check the stores ... Dell 36 month warranty... HP, Acer, Sony, etc... 12month warranty.
If you have R12k to spend talk to a reseller and get the upgrades you want. Otherwise goto Game buy one for R8k and then spoil yourself with a day at the spa! (lol)
Good luck for your studies dude.