If you are looking for a good looking phone with a video camera and amazing colors buy this phone. If you are a J2ME developer keen to move test MIDP 2.0 applications that make use of the MMAPI in a real phone give this one a miss.
As already mentioned the MMAPI implementation in this phone certainly needs some serious improvements. If in doubt just take a look at the known issues document. It runs well into 15 pages and the MMAPI is not the only area that has been covered.
On the other hand if you are building a MIDlet that needs a lot of memory or storage the Nokia 6600 may be the right one for you, but keep in mind that each record has a maximum size to which it can grow. You can fit in extra memory so you can move all your images and videos to the add on card to free up main memory.
Check out the downloads page to obtain the source code for the MIDlets discussed in this review along with a packaged jarfile.