I've got two DLG's they are great fun, but they have power - The power of the human arm. In a no lift condition it's all downhill after the arm does it's bit.
Here's a couple that give some impression of how much energy the launch gives.
This is my Elf micro DLG with a keychain can velcro'ed onto the wing.. On an 80g model the weight and drag kills the performance stone dead but still interesting.
View out the rear window: