Hi, I'm having this exact same problem too (after finally installing this update to 6.0.1) on my galaxy s5. In swype (in gmail, or texting, whatever), hitting the backspace/delete button once immediately after entering a word with swype + predictive text used to immediately delete that last word. Now it just backspaces a character at a time. Super annoying.
I tried the suggestion in comment 5 but it doesn't work (or rather, I don't see any such options).
As Swype's own developers explained a couple years ago, "Swype is rarely off by just a little" - if it's not the word you want, you want to delete it, not fix the end.
How do I do this in 6.0.1?
Thanks!