Ok, so this is coming through a bit later than I had planned, but I finally had some time today (being a public holiday) to write up my experience with using the Acer Iconia W510 for a week as my main device. Unfortunately, I never really got the chance to use the Win 8 tablet as my sole device not because of lack of time, but more because one of my other devices (ie the iPad 3) was more useful to me. Basically, I can boil down the reasons why I would always end up picking the iPad 3 over the W510 to two things:
1) Apps - I play games a lot on my iPad (my current obsession is a great dungeon crawler called Dungeon Hunter 4), and for now, it's a game that's only available on iOS and Android app stores. This means that during my leisure time I'm staring at my iPad 3 slaying bad guys and collecting gold/loot, which doesn't leave much time for any of my other devices.
Outside of playing games, the type of apps I like to use on my devices are: Twitter, Instagram, Buzzfeed, Youtube and the browser. Of those apps, twitter is still a little buggy, Instagram and Youtube are non-existent, Buzzfeed is crippled, and the browser (which is good, but a little glitchy at times) has to pick up the slack. The overall result is that my experience with the W510 is a significantly less polished (which makes since this is a 1st Gen Win8 device) than on the iPad 3.
2)Cellular data - The W510 model that I purchased was the WiFi only model, while my iPad 3 is the 3G model - there is a 3G model available on the Acer online store, but not on any of the brick and mortar shops that I've visited. This isn't really the fault of the tablet (though it would have been nice if it was easier to impulse buy), but it does mean that if I'm out and about, to really use the device how I'd like (ie access social media and web services) I'd have to use my phone as a hotspot. Though it works ok, the process involves enough steps and compromises that most of the time I just use the phone itself, and the W510 stays unused in the bag.
So as much as I love the W510 and Windows 8, my iPad 3 still wins the fight on which device is my daily driver. I do sincerely hope that Microsoft can somehow encourage more game developers to port their games into Windows 8, or at least stop scaring them away by forcing them to integrate with xbox (I don't know if that's a thing or not - just wild speculation) - because this would make the process of switching from one of the more established platforms (Android and iOS) easier.