Tried a few 535 demo units and all of them have low screen sensitivity. I had to hold my finger firmly, especially when using Wordflow to enter words.

Seems like Ars Technica has noticed this problem as well:

The one sticking point I had was not with the image, but rather with touch. While it was generally fine, on a few occasions the screen was slow and imprecise when responding to touch inputs, requiring multiple stabs at the screen to make something happen. This wasn't a consistent issue by any means, but I've seen similar reports from others testing the phone, so I don't think it's an issue unique to my test handset.

This post has been edited by Andrew Lim: Dec 13 2014, 06:44 PM