This topic was about 7" vs. 10" tablet though, and whether or not you can see yourself needing both.
I still think regardless of whatever screen size you're comfortable with on your phone, it is going to be really hard to justify both a 10" and 7" tablet in addition to that.
added: I guess when he said "having a phablet eliminates the need to carry a tablet alongside a phone", I understood it as: you may get a tablet, but it's not for something mobile, which means might as well get it with a 10" screen.
Well yeah I'm of the camp that believes the 10" form is the right way to go. It's nicer for reading and surfing and stuff. I do agree weight could be a factor but we all know the iPad is on the heavier side of the spectrum.
The 7" form factor starts blurring with larger phones and I believe with even 4.8" phones it starts to come close. I don't see a 4.8" replacing a 7", but I don't see a need for both 7" and 10" if I have a 4.8" phone already. I could see the 7" being more useful if you have only a 3.5" iPhone which reading might be annoying on.
The OP deals with a Windows 8 tablet and I find that to be very different. The reason why I get an Android tablet versus an iPad are two different things. My CM9 TouchPad was for modding and installing crazy stuff. My iPad 2 was for consumption. You can mod your Android tablet, but I'm pretty sure the Windows 8 tablet will be locked down. For me that already spells two different purposes. Even if it weren't for ROM flashing, there's still a lot of customization and I see the Android tablet as a eccentric gadget. Meanwhile the Windows 8 tablet won't have all content available, so it's really an apples and oranges decision.
If you're only evaluating form factor, you should ask yourself if there was a Nexus 7 and 10, would you have both? Or if there's an iPad mini and an iPad regular, would you have both?