I'm probably one of the few out there that will say that the Simple Soarer is a great glider for slope soaring. I've flown it several times down at our local beach, and have had lots of enjoyment hucking it off the cliff and catching a breeze. The dihedral in the wing makes it easy to keep stable, and you can glide for hours on one battery with it if you are going for a true glider and not something power assisted.
That said, it IS more fragile than some planes out there, and may not hold up to hard landings. I nosed mine in on the first flight, and broke the swappable pod for towing just in front of the firewall; all I had to do was rebuild that section and stick it back on, and I was ready to fly again with the same fuselage and wing.
Keep in mind that, regardless of whether you go with a Versa Wing, Tiny Trainer, Simple Soarer, or any other plane, if you run it with a prop on it, you WILL experience drag when trying to slope soar, and it is noticeable. You can fly with it, just expect it to not perform as well as if you were running without it. And if you should decide to build a plane and leave the prop and motor off (i.e., the Tiny Trainer or the Spitfire or the Versa Wing) remember to balance your plane accordingly. Your plane will no longer have that heavy motor pulling it down in one direction, and so your battery and other components may need to be shifted more in towards your balance point.