I have the Nexus 7 and until I rooted it with SentinalRom,something I never intended to do, it was on the fast track to Craigslist. Not that is isn't still going, just not today.Not very long. While I tend to agree with you, I can usually see the signs early on. On my nexus 7, I could see some issues from the beginning and that it would only get worse. Also, I don't plan on doing a lot of customizing (such as live wallpapers, different launchers, etc) that tend to cause issues.
But I digress. I can't disagree with you about how smooth the Optimus G Pro is because it is. But its one of those things until you get one home, you only get to half the picture. My son reviews these things for his blog so we get review units in. I've had one over a week as a daily driver. The first thing I notice with this is how decent the battery is for such a large display. I got almost 2 full days on it. It also has built in QI and if i sit it on my wireless charger, it charges. Camera isn't bad and I did like the photo management.
It runs pretty well with the few apps I installed on it. And its thin. So thin in fact it feels emaciated for lack of a better word. I'm used to the heftiness of my L920 but got used to it after a few days.
One day I opened the flood gates and let almost my full complement of android apps have at the Optimus G Pro. And while I agree some android developers are worse than others, apps like Flipboard, that ran great before, developed a noticeable stutter. It wasn't constant and not easily reproducible but definitely noticeable. Several others did too. My Lumia 920 is pretty thick with apps and games and I have yet to experience lag. But props on the compare and contrast post.
I am curious about something though, what are your thoughts on the HTC One?