I don't think it is the new Start screen per se that gets people up in arms. It is just the overall clumsiness to operate Win8 on a desktop and the quasi total lack of new and exciting funtions that will make people think twice before they invest any money into it.
There are certainly a lot of changes 'under the cover'. But they do not manifest themselves easily. Some of the performance tweaks had to be done because of the tablet specs. But for a desktop with an i7, 8GB of RAM and a couple of SSDs they do not mean much.
I was able to do everything in Win8 that I am doing in Win7 - but it was not any easier or more elegant or more anything - just the opposite. So why bother.
I would love to buy Win8, but refuse to buy an OS for desktop work that forces me to use a Tablet/Smartfone GUI. And which lacks a legacy start menu; and where it's necessary to use hacks or work arounds to get what I already have in Win7.
Show me the more bang for my buck!
For this reason I have unistalled Win8 as there is no point wasting any more time working with the system.
With a high end Intel mobo and CPU, SATA3 SSD HD, 12GB of RAM, USB3 ports for external storage HDs ... Win7 absolutely flies, and fulfills my wildest expectations!
Add to that an Acronis back-up image of the fully loaded OS on a storage partition on the main HD as well as on an external HD, and all my personal data stored on both. So in the event of a total system crash, or my HD even being nuked, I can restore it all back again literally in 12 - 14 minutes, including updates using ADSL3 hi-speed iNet. I can drag/drop 3GB of music from the storage partition on the HD to desktop in 42 seconds.
I mean, what more could you want? In fact I think Win7 has peaked the ultimate desktop OS, except maybe for the few tweaks and corrections in system programs in Win8.
So why aren't those improvements offered as Service Pack 2 for Win7? They at least owe us that much!
I've been using a Tablet GUI on my Sony Ericcson Smartfone for the past 12 months. Ever since the get go I've shaken my head and thought: What a stupid, inept system that doesn't hold a candle to a normal desktop! It's a joke!
But then, horror of horrors, M$ are forcing my worst nighmare on me with their latest OS!
A smartfone is actually half-phone, half-computer and not really good at either. Try typing a word document on a screen the size of two match boxes! And reading a web page in 8 or 10 parts because you need to expand the image size to make it readable. My old $50 Samsung mobile has more than 20 preinstalled functions that I have to download as apps on the $600 Sony ... and that's progress? Well yeah, I guess it is for the companies selling the apps.
If Win8 turns you on, I say go for it! And the best of British luck in using it. But where is the choice built in for those that don't like it? One OS for all platforms is like having one engine for all types of motor vehicles.