There are lots of alternatives to the Radian. You're really missing out if you stick to foam gliders...they just don't have the performance of the real thing.
I'd say one good competitor, though, to the Radian, would be the FMS Fox. It's nice and big, docile in flight, and has the legs to get out to the lift and then get back, even in wind.
If you're willing to do some assembly, the Hobbyking "Big E-Fair" is way better than the Radian.
Hobbyking sells, or at least used to sell, a 2 meter called the Deamon. It's a very, very good performing airplane. Unlimited vertical in the climb, but it really floats beautifully. Not a beginner's model since it'll punch through 100 mph pretty quick in a shallow dive.
Art Hobby sells some really nice gliders...some of them are quite affordable (we're moving up in performance as the suggestions go on here). Quite rugged airplanes too.
If you can find a kit for it, the Sagitta is a real performer. Very wide speed envelope. Not hard to convert it, or the Mirage, or the Aquilla to electric power, and all three remain competitive with modern sailplanes.
If money is no object, all of the above pale in comparison to this guy:
Kennedy Composites Electron I flew one this past weekend. At $470 for the airframe, it's really a lot of airplane for the money. Amazing wind penetration, and it will thermal off of the slightest wif of rising air. It's also *very* easy to fly...nothing intimidating about it at all. On a small Hyperion GS-30 series outrunner and a 2s 1200, it has unlimited vertical.
Edit
Just saw that you're looking for non-aileron airplanes. So...
The E-Fair has ailerons, but I'm told that it flies fine using just rudder and elevator. Art Hobby sells several rudder-elevator models...they fly great.
The Electron is Rudder-Elevator-Flap. You only use the flaps for landing, and for thermal optimization mode if you wish to do that.
Most of the big thermal duration models are some variation on rudder-elevator. You need either flaps or spoilers to get them down. No, really. You'll never get it to land where you want it without them. They fly that well.
Almost all of the older wood gliders are rudder-elevator control. This includes the Gentle Lady, Olympic, Sagitta, Aquila, Mirage, Paragon, Bird of Time, etc. All of these require conversion to electric if that's what you're after. It's a piece of cake to do it and you're missing out if you don't.
RES gliders are very popular these days, including the Ava, Pulsar, Bubble Dancer, etc. Expensive birds, but they're easy to fly.
Let's not forget the Bird of Time as a very good economy class 3-meter (and still one of the greatest glider designs in history--still very competitive). It's two channel and you can drop in an e-power system as a substitute for the ballast needed to balance it. Have fun getting it to come down though! Available in kit or ARF form.
