I don't get the idea that it's somehow easier to sift through the start screen rather than go through all programs in the event that the thing you want isn't in the most commonly run programs (which, incidentally, the new Start Screen has no equivalent to).
(My points are from a Desktop PC running Win8 Pro. I know nothing of RT at this point...)
I don't see it that way at all. For one, I absolutely hated the "Frequent" list generated on Win7 and always turned that off. I know what I use most frequently and I would Pin it to my start menu.
That "Pinned" start menu that I speak of is exactly what Windows 8 Modern UI screen is and it is a hell of a lot faster to navigate. If one takes the time to organize their new start screen in to categories of their choosing and unpin items that they do not use that often then it is even easier to navigate.
It can be brought up the same way the win7 start menu is triggered. Either by a box at lower left of screen or by hitting the Win key. Also, unlike the windows 7 start menu, you can quickly scroll through the Win8 start screen with your mouse wheel.
Right Clicking and showing All Apps is a bit unruly to sort through. Some header distinction would go a long way there for quickly honing in on the section you want.
As for searching... Why on earth would you search from the charms bar for a file?
The new explorer interface is a snap for things like that and just like anything else with Windows 8, you have to take the time to learn the new system. Once you do, and develop some new habits then they become second nature, just like the habits we all built with 7 and XP.
One helpful thing that I did was to add a "Computer" toolbar to my taskbar. Right click, toolbars, new toolbar. Click on Computer in the left pane and you have it. Turn off text and title and you have a nice equivalent of the old Quick Launch toolbar.
As for customizing Win8.
Decor8 was an excellent beginning and I greatly look forward to more.
Start8 is just a crutch and serves no purpose at all for those that want to take the time to learn the new system. In panic, I installed it at first, but once I forced myself to not use it I easily discovered that I was better off without it.
OblyTile is another good start for customizing those tiles. It isn't made by Stardock but I would be that you guys have something in the works along those lines. If not, then shame is upon you. .
Also, I look forward to seeing what windowblinds8 will bring to the table. If it is a step forward then I'm in. If it's a crutch which brings Start8 in to the picture, then I'll pass.