[Galaxy Note 10.1 (2014 Edition) General] BarryH_GEG:
The first challenge is there's no common definition of "lag." So one person's "OMG! It lags!" is as purely subjective as another person's "Mine's lag free." There are two places I notice what could be called "lag." Transitions (EG: moving from home screen to home screen, app openings) can sometimes show a millisecond delay or stutter. Some of Samsung's more resource intensive apps (S Note, Scrapbook, Action Memo; especially sharing between them) can sometimes display a spinner while processing. Since no other device offers multiview and S Pen optimized apps on their devices it's kind of hard to fault Samsung for their performance with nothing to benchmark against. I have never experienced any delay or lag when working within a single specific app. I also don't notice any keyboard lag when using the stock onscreen keyboard.

There's no question my N3 is a lot more responsive and fluid than my N10.1-14. But when you consider the display area the N10.1-14 is supporting (10.1" at 299 PPI vs. 5.7" at 388 PPI) that's a hell of a lot of additional workload for the same CPU/GPU to carry. The N10.1-14 was pretty rushed by Samsung to get it on the shelves before the holidays as evidenced by the lack of multiuser support at launch and subsequent addition of it. Samsung's been on a mad pre-holiday tear to get the SGS3, SGS4, and N2 moved to 4.3 so that they could support the Gear. Hopefully things will settle down and the N10.1-14 will start to receive some performance optimization updates. I came from a N10.1-12 and think, with the exception of some random transition lag (+/-5-10% of the time), that the N10.1-14 outperforms it in every other way.

As for individual devices performing differently of course they will. It depends on the quality, quantity, and how current the apps people are using are. Legacy apps and performance monitors aren't optimized for a 2560x1600 resolution display and could easily be creating behind the scene conflicts or resource usage.

I have 142 apps installed and 26 home screen widgets running along with nine background syncs. I'd rate the N10.1-14's overall performance as an "8" on a scale of 1-10. I'd rate my N3 a "9." I don't think any device with an OEM overlay could ever achieve a "10." How people judge their devices depends a lot on how they use them. I truly wonder if some of the people pursuing the Holy Grail of the "perfect" transition actually even spend any time using their device for anything other than flipping between home screens and opening and closing apps. The Note-series is all about productivity and creation and there are a ton of resources used and in play to facilitate that functionality. If the price I have to pay for that functionality is the occasional millisecond long stutter moving between home screens or apps I'm fine with it. If all that matters to someone is how fast and fluid their navigation is they shouldn't buy any device with an OEM overlay. But if those same people buy a Nexus (or use an AOSP custom ROM) and then load it up with a ton of third party apps (some of sketchy quality) to replicate all the features from TW the resource drain they create will get those people right back to where they started in the first place.