I've got the medium one of those. They are very good for the money, and built like a tank. The handle is very comfy too, much better than the thin rubber strap you get on most cases. Inside you get a plywood board sprayed black and some velcro to which you attach your pedals. I screwed rubber feet onto the bottom of the board to raise it so that I could feed cables underneath and also to raise the pedal height which provides better contact between the pedals and the foam in the lid (as the case is pretty deep). I've also got some fluffy speaker cab cloth and spray glue from Maplins which I was gonna fix onto the board to provide 100% covering.
They are very bulky though and weigh quite a bit (the xtra large one will kill your arms when loaded with pedals, better get working out!). If you want something slimmer and lighter the Diago boards are great, and the Pedaltrains look pretty cool. But then again, the Spider is hard to beat price wise.