It's the tradeoff of speed versus weight, battery time and maybe cost. The problem is that your work may not be my work. For example all the apps our office works with compile in under 60 seconds on our oldest Core 2 Duo laptop without any upgrades.
Your new machine may have twice the ram and either SSD or a much faster HDD.
I'd go with what you like best as my bet is this is an upgrade to what you use now.
I'm having a hard time choosing between the Dell e6540 (quad core i7-4800mq, 15") and Dell e6440 (dual core i7-4600m, 14").
I'll be using it mainly for programming across multiple environments simultaneously, with a fair bit of traveling.
I know that the quad core will give me better performance, but I really like the smaller screen size (my current laptop is a Dell 15" 1558, and I find it a bit too bulky).
So my question is:
How much will a quad core help my performance against a dual core? (preferably the 4800mq vs the 4600m)
And is this difference worth sacrificing portability for, in your opinion?