It's a bit strange for me to see people ragging on the Radian for not having ailerons -- because, the fact that it doesn't have ailerons is its primary attraction for me! RE is the classic recreational glider setup -- think 'Gentle Lady'.
If you want ailerons, there are a ton of models out there. In the electric-powered foamie category, there is, for one, the very popular Easy Glider Electric.
For thermal soaring, ailerons actually aren't particularly useful. A properly designed sailplane with a polyhedral wing will pretty much automatically coordinate your turns for you [with the pilot only using rudder]. Aside from that non-use (coordinating turns, that is), there's not much to do with ailerons on a sailplane besides fine-tuning the wing camber and making final approaches (particularly when deflected up as spoilerons) and spot landings. Actually, that is quite a bit, isn't it?!
That's of course why many people fly "full house" [REAF] gliders. With non-electric gliders, slightly drooping the ailerons can give extra height on a hi-start launch. This kind of wing chamber can also be useful thermalling. When traversing an area of sink, ailerons might be put in a different camber to get through the sink faster. Okay, so there's a lot you can do with ailerons! However
, this is really very much 'fine-tuning' sort of stuff.
If you're really into the performance of your sailplane, you'll want to invest in the appropriate [full house] aircraft and radio. The Cularis might be a good way to get started with that.
Also, ailerons can be used to amuse yourself with aerobatics on the way down. Or you can just motor around with the motor on and use it as an airplane. If that sounds good to you, then the Easy Glider Electric is probably the way to go.
, the basic idea of a thermal sailplane is that you go up a few hundred feet (which in our case is more than solved by the electric motor), and then you glide around [in a pattern] searching for lift. This gliding is done basically in a straight shallow descent, and then eventually with a shallow to medium bank turn to enter a new leg of the pattern. When your aircraft indicates lift, you [attempt to] turn into it and go up! You then continue turning (in circles), attempting to keep your turns centered in the rising (and expanding) bubble of air (that is, the thermal). If you're skillful and/or lucky, you can ride the thermal all the way up until the aircraft is becoming in danger of disappearing from your sight. Either when you lose the thermal or are forced to abandon it (because of going to high or too far downwind), you enter a level glide (probably after turning back toward your field, if you've gotten far away) and resume a search pattern for another thermal. The point is, thermalling generally involves long minutes staring up (with your neck craned backwards) at a small shape in the sky that you control to turn circles. Ailerons aren't important for this. In fact, if you have a flat wing and ailerons, it's a lot of work to keep the plane level and coordinated when it is so far away (which is hopefully most of the time). Remember -- hopefully its way up there and you can barely see the thing!
For sloping though, where the aircraft is right there in front of you, ailerons definitely make things more interesting. The Easy Glider isn't a dedicated sloper, nor is it a dedicated thermaler. It's more of an all-arounder. It can be used to thermal, and it can be used to slope, both with good results. In the electric version can be flown around as a park flier airplane
I have and enjoy an easy glider electric (actually two of them, plus a third nonelectric easy glider), but what looking for now is more of a dedicated thermaler. Basically, I'm looking for a[n electric-powered] foamie version of my Sophisticated Lady. Or you could say, a more dedicated glider version of my Easy Star. Something that's inherently stable -- an RE ship. Something where I can just concentrate on the hunt for thermals and staying within them, while the plane meanwhile basically flies itself. I want something relaxing, where I also don't have to worry about all sorts of complicated mixes on the radio. It's looking to me like the Radian is the plane for me!
Sorry for the long post, but I just wanted to explain why a lot of people are going to think the Radian is a cool ship. Parkzone didn't "drop the ball" by "leaving out" ailerons, but rather RE is an established sailplane category. It's a category especially suited for beginners or those who want to have very relaxing flights -- which is the category of pilot that the Radian is aimed at. If you're looking for a glider with ailerons (which is a very legitimate category!), simply look for a different aircraft. Maybe Parkzone will eventually put out a model in that category too. But the rudder -elevator Radian is in a different category, one that many pilots will enjoy.