||I'll give the bottom line first:
Excellent value for your money! Flies very well once set up. Mine is only 3.25kg with a 900watt motor on 6s in the nose ... so it can be built very light for a 4m ship, and is very capable of thermalling. However, you should be prepared to do some work/modifications to get good performance in the air .. or you will be disappointed.
9/10: Glass Fuselage.
My fuse is light and straight; some others I know had twisted vertical stabs, which can be straightened with careful treatment with a heat gun. The paint is hard and somewhat fragile - it will crack if mistreated even a bit. Some bulkheads were not properly glued all around their perimeter, including the stiffener in the fin. No a big deal, but watch for it. Both canopy and cockpit need very careful trimming to fit the fuse well: I tried very carefully and would only rate my fitment at 80%.
6.5/10: Balsa built-up Wings and Horizontal Stab.
My wings had differing degrees of washout. You can't twist the wings into trim - they are too stiff unless you remove the covering and steam. So to fix, I relocated the alignment pins at the wing roots and warped the flaps and ailerons a bit. I definitely see the misalignment at the wing fairing, but this is cosmetic and others may not even notice. The other thing: the flaps and ailerons are from balsa stock, so they don't match the airfoil shape especially well. And the ailerons end far short of the tips, so they are not especially efficient at rolling the glider. Oh - the tailplane is also built-up, is over scale & heavy. I made a new one for half the wieght and true to scale dimensions.
Standard fare connects the various systems together. I discarded their rudder and elevator actuation systems for lighter and better systems. Certainly the stock stuff works, but most builders will have better and lighter bits and pieces to use laying around their workshop. The canopy hold-down system is a rubber ban; this is poor and if I were Fly-Fly's tester I'd have recommended a magnetic hold-down approach. Cotton thread has been taped in place to aid with fishing the servo extensions and rudder actuation wires. The supplied wheels are light but weak and offer no shock absorbtion ... plus my front wheel has a major flat spot. Suggest replacing with something more functional & attractive.
They are obviously designed for the experienced pilot and builder, and provide bare minimal guidance for the novice. They are of the ARF sort - and AFF's tend to attract the novice - but this plane has sufficient need for tweaking that these ARF-style instructions only get a 7 from me. There's not a lot of verbiage, with minimal setup guidelines. The stated CG is safe for a maiden flight, albeit forward of ideal. Control throws are ok, but make no mention of coupling the rudder to the ailerons. Now of course experienced pilots will recognize the dismal roll behavior and instinctively add gobs of rudder the first time they attempt a turn. But the roll behavior is SO poor that I think mention ought to have been made in the instructions about coupling the rudder.
As mentioned, I built my kit as a motorglider to chase thermals. However, I did not use the Fly-Fly recommended approach to making this into a powered glider, which is to mount an elevated pod behind the canopy. Rather, I used a 500kv motor on 6s 2200 mah Lipoly cells to drive 900 watts through a 15.8 folder in the nose. The DG-808S has such a narrow nose that I needed to use a motor shaft extension. This setup will lift my plane nearly vertically from a handlaunch.
I'll reiterate that in order to have decent control over the roll axis, you will need to have major coupling between the ailerons and rudder ... along with serious aileron deflection at 2:1 differential. The net result, however is a plane that is easy to fly, resistant to tip stall at 7 lbs AUW, and a pleasure to chase thermals with. Indeed, all sins are easily overlooked once the plane is trimmed and tuned - it's a very nice flyer and very pretty in the air.
Here is a thread where you can read more feebcack from others who have purchased the 4 meter Fly-Fly DG-808S Sailplane: http://www.rcgroups.com/forums/showthread.php?t=1050816
Hope this helps!
Rating: [5 of 5 Stars!]