DeskScapes and WindowFX 4 both are resource hog and unproductiveness,got it?! Mate.
It depends on what kind of computer you're using. Is your PC rather old (like a few years or more)? I've got DeskScapes, WindowFX, and WindowBlinds running simultaneously on my new desktop PC (which I bought just 2 months ago), and my CPU Usage is usually below 20%. For those who are curious, my PC has an AMD Phenom II 945 Quad Core Processor, 8GB of DDR3 memory, and an ATI Radeon HD 5450 graphics card (stand-alone graphics, not integrated), so it can handle ALL that plus everything else that I can throw at it like image editing, web browsing, running Office and virus scanning simultaneously without any slowdowns.
Heck, my OLD PC, which is now over 6 years old, couldn't handle running Deskscapes without the CPU spiking to 100% usage (it had a single-core processor). Even a simple virus scan slowed it WAAAAAAAAAAAAY down to the point of absurdity. I'm glad I don't use that piece of crap anymore.
The point i'm trying to make is that if you've got a fairly new, speedy PC, it shouldn't get in the way of productivity and your PC should run every bit as fast as if it wasn't running those programs. But as for aesthetics, the animations (depending on which dream you use), can get rather annoying. If you're editing images and running WindowFX, don't set inactive windows to darken. I found this to be annoying myself. You just have to tweak the settings until you find it to be just right (for you).
I apoligize for my response being kinda long, but I just want to get my points across.