I too try to print without support as much as possible, but some times it is unavoidable. I DL'd 1.1.5 and decided to do a test using some JustABS filament that I just got in*. This is a test print for another GoPro helmet mount. This one is for a friend with very specific angle requirements so I wanted to test a slice of the object without printing the entire mount.
Both were printed at 2.5 layer height and sliced with Slic3r 1.1.5 with all the same perimeters besides support. The left has support spaced 2mm with 3 interface layers. The right side object has only custom support made in MeshMixer. I haven't had the time to try slicing in MeshMixer yet.
The first image is the object in MeshMixer with some custom support that took me just a couple minutes to add. Would have been seconds if I was more familiar with the program. The support took no time at all to remove with a razor, and did a very good job for this test print.
The left object had way too much support, was very difficult to remove, and basically ruined the print. I wouldn't be able to insert the GoPro without additional cleaning. I could make a better print if I played with the settings, but the MeshMixer mount came out so well I don't think it would compare.
If you do decide to give MeshMixer a try I strongly recommend resizing the object before doing anything. I went with 10% and it processed alright. When I try doing support on a full size object I've had it take up to 20GB of RAM and like an hour to analyze the object before I could begin. Reduced it doesn't take much time at all and I have a pretty fast machine with 32GB RAM.
* Don't really like it compared to my normal Octave, but it was half the price so why not give it a shot. Going to see if i can get better prints with it. If not I will probably buy it just for test pieces.

E3D-v4 Hotend, MK5 carriage with round plastic wire conduit , 3/16" tempered glass, Well nut, SureStepr SD8825 1/32 Extruder Driver, PowerEdge 2650 500W PS, QU-BD heated bed, circuit board fan, hinged plexiglass enclosure with plastic tray top. Other than that mostly stock SD3