I just upgraded to the Panny AE-4000 from the AE-2000, previous to that I had the Sanyo PLV70 ( 2000 lumens, 900 contrast ). I have always used a DIY BOC screen with great results. I actually just now figured out from taking sensor readings to tweak my 4000 that I had totally forgotten I had used a darker grey, non neutral color paint back with I had the Sanyo with low contrast. The new Panny has some much more contrast ratio than my first PJ, the Sanyo. I love the pic. I have always loved the pic, but want to get the best image possible so I am experimenting with some lighter, more "nuetral" grey colors. IMHO you should definitely build your own to begin with if you have any skill with a mitre saw and are somewhat handy at building things. What do you have to lose? At one time I ordered some samples of screen material from Da-Lite. In comparison on my Sanyo I did not see that much difference. You do DEFINITELY want to paint the BOC with some type of neutral grey. I had read that projecting on the native BOC the pic looks ok, but is compared to looking through a dirty window. Once I painted mine I discovered what was meant by that statement, the image became clearer, especially in high def.
There are plenty of forum posts that will make your eyes bleed from reading them, about how to build your own screen. Allot depends of course on ambient light, size of room, type of Projector, distance from screen etc. For the AE 3000 you would probably go with a light neutral grey, again depending on conditions in the room.
One thing I will caution about. When you paint the BOC ( preferrably spray versus roll, but I have rolled and it can be done without edges in the finish ) you will have to lightly sand the screen. BOC will raise a bit when painted, just lightly, very lightly sand it. But, if you have a wood frame behind the material and sand and push down on the screen a little too much it can cause "edges" for lack of a better word to appear where the wood framing is, so be careful of this.
I found this to be a fun project, one that does not cause headaches, moves along pretty quickly and gives you the pride of accomplishment. One thing you might do is buy a sample test piece of BOC and start with no paint, look at the image, then have another sample piece and paint it a light neurtral grey and compare and go from there. One of the light neutral grey colors that is heavily discussed is a Behr 1070 from Home Depot. That might be a good place to start.
I imagine if put side to side in a dark room a da-lite screen material would probably look a little bit better, depending again on room conditions etc, but maybe not that much that it is that noticable compared to money spent. You can always upgrade to a manufacturers screen in the future. But you will be happy with a DIY BOC screen done properly. My friends jaws all drop when they visit my theater and see the pic.
Build yourself a frame to put around it, with some type of black material, felt or whatever to absorb light reflection and it will help out the pic also.