Sorry to take so long to jump in...been running a bit and wanted to take another picture. I put my Dynon SV-32 roll servo in the fuselage...outer left bay, as Paul did in Mikey. No reason at that time other than it was per the Dynon instructions. I'm sure Sam's and others' wing installs are fine, but I'll pass some of the things I learned along the way, when installing into a bought-flying aircraft, with lotsa stuff in that bay to work around.
I would try to get the servo as far aft in the bay towards the spar as possible...or at the very least, make sure you test the space between the aileron push tube and servo rod end (at the servo arm) in the bracket position you want...before you drill the bracket holes in the fuselage. The closest point of approach between the two happens at full fwd, full left stick, as shown in this picture (its close to full throw in this pic anyway):
Due to the plastic snap bushing where the wires penetrate to the left of the pic, I needed to trim the bracket a bit (you can see the left side of the bracket curves around the bushing). As it turned out, I have good clearance from the push tube, but without the wires and the bushing, I could have gone aft another 1/4", and the clearance would be just a bit better. Not sure if there is any coupling due to the slight forward angle of the servo push rod as was mentioned earler. I've had pitch oscillations at times, but it does not correspond to a roll input (that I can tell). Pitch issues are intermittant, and seem more associated with the AP chasing than the roll servo coupling (IMHO). Roll has been pretty nice...as long as my ailerons are in trim!
At the other end of the aileron throw, the same rod-end was contacting the side skin at the aileron push-tube hole edge, so I also cut a little notch in the hole edge to allow for clearance. Not sure if its the same as Paul did, but it's as shown here:
The fore-aft orientation of the bolt in the rod end bearing was necessary to clear the aileron push rod at the other end of the throw, so the nut had to go on the back, which made the notch necessary. On the pitch servo, the bolt is the other way around, so the shoulder of the bolt is riding in the servo arm (it was the other way 'round, til Dan H and Mike S pointed that out in a post after the install two summers ago). Couldn't do that on the roll servo, due to the geometry, but (as Dan and Mike also said), its a small enough bolt and small enough forces that the stress on the servo arm bolt should be minimal.
The servo looks a little cocked in these photos, but its the angle of the pics...it's in line with the ribs.
After the install, I decided to make a little viewing/inspection panel so I could check that it was staying together well and maintaning the clearances. Probably more of a distrust of my work...the panel/AP was my first big project on the plane. I just cut a small rectangle out of the floor, made a plexi overlay, and used four of the existing floor nutplates to mount screws and tinnerman washers to hold it in place (the two left screws are hidden under my velcro-in side panels):
Probably overkill, but I can always make a quick check from time to time. Of course, I do pull the floor up on condition inspections...and I've had the floor up more than I care to admit, due to radio and antenna work.
Speaking of antennae...you'll see that I have a comm antenna in the bay just to the right of the servo. During the panel upgrade, I moved it there from the center of the fuse at the same station line. I then put a TED antenna in the middle for my Monroy, then put comm 2 on the opposite side, in the same bay (second from right). Turns out that puts the comm 1 & 2 only 27" apart (rather than the 36" recommendation) and I have bleed over into comm 1 from my comm 2 or my APRS when I run them on that comm 2 antenna. I only described this, so you can plan around that. Your antennas may be in different locations already, but if you were thinking about doing them in those bays, I just wanted to pass along my results, likely from being too close together.
Overall, its easy to get to (floor pan screws notwithstanding), a bit tight to get in and out, but not bad really, and the wiring was perhaps made simpler by being in the cockpit. I don't feel qualified to recommend one location over the other, but just wanted to pass on a few tidbits to add to your database!
Have fun and good luck!!