ORIGINAL: Mastertech
My observations,
On the single push rod Y support only at the rear will allow the metal rods to twist and bow between where they join the push rod and the control horn, this is why most used 4-40 rods to try and solve this and also adds weight to the rear of the fuse. Also once the aft support tube is in it must be perfectly aligned with the servo or binding occurs, this can also happen in high G situations. Easy to change a servo.
The shorter Y with the bearings in the fuse sides is lighter and places the bearing surface much wider and therefore more stable. Easy to change a servo.
I do like the deps system and if building a wood Fuse is the one I'd most likely use. It is a major PITA to get true in a built fuse. It is also fussy to get right. Changing a servo is cake.
The best overall system for stiffness is twin servos in the tail, only draw back is that much weight that far back and the fact you have to re trim the elevators if you have to change a servo. This system while a PITA to change a servo has saved me one plane so far when one elev servo died.I've used the pull-pull on elev and while it is the lightest, it's far fussier to setup and can change as time goes by. Easy to change a servo if need be. Not one I'd ever use again.
Twin push rods using twin servos at the front is easy to install but redundant. Heavy as well.
The MK bell crank is not even a player in my book, this syetm has the most slop of any system in my exp.
All in all every system has it's plus and minus. Pick what works for you.
My two cents:
My best overall system IMO is the single pushrod and single lever.
Servo’s can experience a lot of vibration in the tail. I never did have a servo of the elevator failed as far as I remember. (Old School!)
Second point is, drag of all the levers, links and iron works visible on the tail, impressive but a source of drag and only commercial interesting.
Last profit, both elevator halves are always exactly synchronized and that’s important for me.
I did show a picture with 2,2 kg (cilindrical piece of steel) hanged on the TE of the elevators of my plane and the position left and right is still symmetrical.
The plane you are talking about is an ideal example to use a single lever system, see my drawing.
Cees