After several hours of using this...imo....
Pros
-symbols are more bold.
-if you forget or miss a space, it often predicts 2 words.
-words predicted are smaller to fit the buttons better.
-bigger space bar.
-after a while, some punctuation is easier.
-quicker, easier speech to text access.
-I've discovered many special characters I didn't notice before.
Cons...
I've been having problems with predictions of contractions. I usually don't have to add apostrophes for it to predict a contraction. (but this seems to be because it is learning my writing style... Hopefully that's all.)
-having two commas makes it less easy to accurately hit the exclamation point (you'll see why).
-now the pressed letter is shown above your finger while it is on the screen. I find it distracting, unnecessary, and even seems to slow me down.
-having small letters in the prediction buttons when the words are small may be slowing me down in landscape mode.
-the letters are smaller in landscape position. (but perfect in normal position, whatever they call that.)
The only thing that would cause me to go back to SwiftKey X is the considerable amount of hesitation. It lags. Along with the keys flashing above the buttons pushed, it slows me down.