Anything wrong with this??

Well, I don't know about that particular RV, by my manual says it's not safe for front or rear wheels to be off the ground and rely only on the jacks for use of the RV. We have used the house jacks to lift the wheels off the ground to change a tire, replace the sway bar bushings, to change the brakes, etc. but a jackstand is always part of that.

I've been considering using the lego-like ramps described here -> http://www.campingworld.com/shopping/item/rv-leveling-blocks-10-pack/56865

Are they safe and reliable?
- Tim