Our soil is mostly sand so we have raised beds with rims about 12 inches above ground level. They are actually built on crushed rock gravel that extends the entire south side of the house and also forms our RV pad. A layer of landscape felt keeps the growing soil from mixing into the gravel. It is great for drainage! I agree they are definitely easier on the back. A couple of things I recommend if you build your own are: No more that 48 inches wide, but not too narrow either because you waste space with too many walkways in between and think about how many rows you will get - for example, 3 1/2 is wasted space too, go for 3 or 4. Add a flat board - even a 2x4 or a preferably little wider centered on the top edges for stability. It's a lot more comfortable to sit on! Plus it makes a nice surface to put things on while you a re working or harvesting. Word of caution, learned the hard way. Whether you miter the corners of the caps or not, cut off the tips at 45 degrees - it saves your ankles! The overhang is no problem, because the plants won't be right up against the sides anyway, but still have the same amount of room for the roots. We also have 1/2 barrel type planters for some individual plants and those that spread. I definitely recommend a drip irrigation system - not necessarily "drip" per se, we use quite a few mini sprays.