So having previously stated that lag isn't a big deal with the 6 plus at all, while I still stand by that, there are one or two moments when it's noticeable.
The reason why I mention this is because I noticed this jitteriness in one of Apple's own apps, which is disappointing.
Try this:
- in iBooks, open a book and use reachability to bring the page down. Notice how there is no lag and it's all buttery smooth as expected.
- now go to the fonts menu (the Aa) sign at the top) and tap it so you can see the options for fonts etc. Now try reachability and, if you're experience is the same as mine, the page will move up and down with noticeable jitteriness.
I've seen this in apps not optimised for the 6 plus, but didn't expect it at all from one of Apple's own major apps. Anyway, that's the only annoying lag I could visibly notice to an extent it bugged me.