Where are you guys setting the CG for 3D flight on the Aeroworks 75cc Extra 260? I just got mine complete, with a DA 85 on it. I flew it for the first time this past weekend, and it flew very nose heavy. I have the CG set at about 3 1/4" (the manual recommends 3"), but the plane wouldn't hold a hover at all. It's definately not for a lack of power, because that 85cc makes it a rocket. I just don't want to move it back too far, and end up with major flight issues.

?????

Planes don't hold hovers, pilots do. Hovering is not how you determine CG. The basics of determining CG are to fly it inverted at level and 45 angles, and also to "feel" the elevator sensitivity in various flight situations.
I don't know what your problems are in a hover, or your overall hovering ability, but if you find yourself having to hold a lot of up elevator, then you are either not fully vertical when you enter the hover, or you may need some upthrust. Or, if you don't reallly feel it "locking in", then you may just be over-controlling it.
What muffler are you using and where are your batteries and what spinner?
I have one of these but haven't flown it, but I had their 100cc 260 for two years. It was not difficult to hover at all, out of the box, but I did add 1.5 degrees of upthrust and it made it to where I didn't need to constantly input up elevator. My CG was set right in the middle of their recommended CG range.
I have one of these planes but

I'm running a slimline pitts muffler and a tru turn spinner, but, the CG check was done with everything in place. I've been flying for several years and am fairly capable as a pilot. I've had two other giant scale 3d planes, including another 33% Aeroworks, that I've had no problem with, so I don't think that the problem is entirely with my piloting (or lack thereof) skills. The plane will not hold a nose up attitude at all, unless I am climbing. I was having to hold in full up elevator just to get it to harrier. I know from doing an inverted flight test that the CG is a bit further forward than I prefer, but I am just trying to get some other opinions and suggestions.

Try adding upthrust, bodeyworks is right the CG has nothing to do with hovering.

Sounds like your flying style might demand an even more aft CG, too, though. Go ahead and try it at their aft recommended range, but I still think a thrust change might be in order.

I've moved the CG back a little bit by moving a few of the batteries back, so we'll see if it makes any difference. I don't want to start adjusting the thrust lines until I have exhausted other means of fixing the problems. I was kinda hoping that Aeroworks would have gotten the thrust angles correct when they made the thing, since I have the setup that they recommend.

Thrust angles can very depending on many variables including: prop choice, altitude, and even how much you tighten the engine mounting bolts. The thrust that is built into the motor box is just a starting point and needs to be adjusted just like the CG and control throws to suite each pilots flying style.

Gotcha. I'm hoping that after a few more flights this weekend, everything will kinda straighten out with it. The DA 85 is still brand new, the plane is brand new, all the stuff in it is brand new... I'm trying to give everything a little air time to get worked in before I start trying to re-engineer the plane. I'm sure that any issues that I'm having are with my setup, not with the airframe.