The Envy for sure!! The i7-4700MQ is about TWICE as fast as the i7-4500U http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-4700MQ+%40+2.40GHz http://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-4500U+%40+1.80GHz
I agree with building a PC. I think you could build a tiny Micro or Mini ITX build with 1 21" monitor and easily fit it on a small desk. You could keep all of the cables off of the floor as well (except for power, but you'd have a power cord for the laptop as well). But to answer your question, I'd still go with the Envy…
So after working hard for me the 5 yrs my old hp G60 finally is going to.computer heaven (but where do all the calculators go??!?!) doing me proud on its 3gb of ram and single core processor with only 512.dedicatd graphics card.. The keyboard and screen is going with the battery and giving up the ghost. So ive been saving…