Here's my experience, and I consider myself a n00b to wings...
First off, I have zero experience with the Spear BUT I have built a KFM wing. If you search around the forums here you'll find all kinds of info on the KFM wing. It doesn't fold over like traditional FT wings, it is actually sheets of foamboard stacked on top of each other. It's an extremely durable wing (trust me I've beat mine good and so far it's only got a slightly crumpled nose). I'd recommend the KFM first before a Spear, only b/c they are quick to build and can take a good bit of abuse.
As for flight, the trickiest parts are getting the balance right (not just your front to back balance, but even your right to left side balance) AND getting the feel of launching the wing. I still have some slight lateral balance issues with mine, but it's much more manageable than what it used to be. Once it's in the air, it's actually pretty simple to fly. It has your typical bank and yank characteristics where you can do all your controls with your right hand...and then just your throttle on your left.
Here is a video of my first ever experience with a flying wing...you can see it took quite a few attempts to finally get it airborne.
I actually flown it again here recently after some tweaks and will have video pretty soon on it. This time it stayed up on my first launch. Still rolled a little to one side, but not too bad. Hope this helps.