Laptops have never been more reliable than desktops for comparable age, use and abilities. Laptop components are a compromise and subject to much more daily stress than desktops, which are constructed of more robust components and usually at a lower cost due to scale etc. For every desktop that came across my bench, I'd estimate at least three equivalent laptops came in for repairs for the same level of use.

However, I would still recommend a laptop for the OP. Since they already have a desktop, they could enjoy the added versatility of a laptop. The ability to go wi-fi or 3G abroad as well as on demand file access wherever they go is quite handy.