The Real Blogger details all this, including how to switch between the two, the new features and the drawbacks. Two of these drawbacks is the loss of the Video button and the Spellcheck button.
If, like me, you both want to switch to the new compose mode (it does make image uploading and page breaks/jumps a heck of a lot easier to deal with!) but you also rely on Spellcheck as a crutch, here is one solution.
- Download Firefox.
- Install the relevant dictionary.
- Restart Firefox.
- Now, as you type, any mistakes you make will be highlighted by a red row of dots underlining the offending words.
- Simply right-click any underlined words to find spelling suggestions.
- Click on the right one to automatically replace it - just like Blogger, only with right-clicking instead of left!
I am sure there are many different add-ons and work-arounds out there, but for a simple, compatible solution follow the above steps. You can also add different dictionaries, for any bilinguals out there.
The one problem with this is that the red dotted line is a bit hard to see. It is obvious if you are looking for it while you type, but to scan a previously written document for mistakes it is pretty tough work.
On a more positive note, this add-on is compatible with all text boxes - comments sections, Google searchs and, best of all, Twitter! However, if anyone has found a better solution, tell us all in the comments.