Laptop gfx cards seem to be hit and miss and just bad in general. I guess for me the ability to upgrade components is far greater than portability for my game dev machine.
Nope , even myl old lap Top with radeon HD 7670, can still run not so old games iwth shaders or Leadwerks 3.
It depends if you plan mobile little games , a lap top will be enought.
Even if LE3 grow or have deferred, i hope in project menu the choice to make a deferred or non deferred game !
LE 3 i hope will keep running on low platforms, caus if you develeop simple mobile platforming game wihtout special shader and little games you should not need a big PC.
You won't travel and have your tower PC with you every where, if your work makes you travel.
Indeed i prefer to dvelop in my PC tower, more power, more fluid, but when i travel, the laptop is super usefull.