The only problem is that you have to use this input instead of any other input. While I can get by without some of the features of the regular, there is a very problematic bug where if you insert an apostrophe (" ' ") in your text it will delete the last word, which makes it very difficult to write in English. Plus it doesn't help you with the regular keyboard. Note: this only works in cupcake builds.
It's also worth mentioning the a12keys app (in the market) which gives you an on screen keyboard plus regular keyboard use in all builds - but it's not a cupcake 'input' - so it works by copying and pasting as opposed to coming up in any input field.
T-Mobile G1 ("HTC Dream")
Haykuro 6.0r1 with atime mod
Radio 184.108.40.206I | Haykuro's SPL
Apps and cache on SD