The ridge-rest is a solid sleeping pad. Super light-weight, durable, and provides great insulation. I'd say it works best as a bottom layer for when you're doubling up on sleeping pads for winter camping.
If you're looking for a sleeping pad for extended summer trips I would recommend the z-lite though. This will work but it won't be very comfortable (particularly if you're a side-sleeper) and it's not the best if you want to be able to pack everything inside of your backpack without having to strap anything to the outside.
Still, this is the best pad you'll get for the price.