i have recently purchased this phone, and after reading the review on this site in regards to messaging functionality, i was disappointed as i previously had the mm-a920, and was hoping for an upgrade in respects to the custom dictionary functionality. as seen below in the quoted review, phonescoop states that this phone does not have functionality of a custom dictionary. The custom dictionary is not only accessible separately (Settings->Display->Text Entry->Personal Dictionary), it also has 'smart' functionality, which is when you enter a word via the regular alpha function, that is currently not in the T9 dictionary, it is automatically added. This is a huge upgrade for me, as the a920 did not support this functionality. overall, i am very impressed with the sleek design of this phone, as well as the improved functionality. it was a toss-up for me between this and the M1, and after i got to playing with both for awhile, i couldn't justify the extra 130$ for the M1, just for an extra .7 megapixels and memory card support when a) i never used the entire 32mb present on my old a920 SD card and b) the picture comparison from the M1 and the A900 did not do a justice of 130$, nor did the M1 2 megapixel camera recieve as good as reviews as i would've hoped. to the phonescoop guys, overall, great review, however, perform a more thorough evaluation next time before commenting about limited functionality that is actually available.
The T9 dictionary comes pre-loaded with many SMS abbreviations but cannot be customized with your own.
Worse, the T9 text entry does not allow you to go back and choose a different word after you have hit the space key when entering text. Thus if you are texting without looking and want to go back to change a word when T9 defaulted to the wrong one, you'll have to scroll back and erase the word, re-enter it and then switch to the proper choice instead of just scrolling back, selecting the word and finding the right choice. Finally the punctuation available while hitting the 1 key using T9 is limited. If you want to use the question mark, exclamation point or many other very common symbols, you'll have to exit T9 and use the symbol entry mode.