I'd be totally stoked to get a Samsung Note sized device running Apollo!
Especially if it was built like a Lumia instead of cheap thin plastic like the Note.
A Lumia Apollo tablet would be incredible and give Apple a run for it's money.
i think 4.3 would be the perfect size. I had a Focus and Titan side by side and the Focus was just a tad too small, the Titan is just a tad too big...4.3 and possibly 4.5 would be just right. But I want to start seeing screens with little to no bezel. You could EASILY get a 4.5 screen in the 900 chassis.
If Verizon would get off their arse they could release a 4.5 Lumia 910 with a 12mp cam and LTE in red and it would be a chart topper. Conversely, I think they could fit a 4" screen in the 800, **** maybe even back in LTE. No need to wait until WP8.