The raimondi and lash are similar and the Tuscan is in a league of its own. There is a huge difference between the two but the Tuscan is a lot more expensive especially if you buy the pro gun for tightening the straps.
You don't have to have a tool to use the lash or raimondi. Both essentially do the same thing though.
They work but they aren't a miracle machine. They are a tool. Just because you have Snap-on tools does that mean you are a professional mechanic? Same applies here, just because you have one of these leveling systems doesn't mean your floor will automatically be flat. The tuscan leveling tools speed me up enough to justify the cost, I can get a flat floor without using it though.