Double edge safety razors may in fact be the best all-around razors ever designed.  They are easy to use, easy to maintain, and also very inexpensive over the long term.  With blades costing between 20 and 50 cents per blade on average, they give you a fantastic value for your money.  I love straight razors, but I still use safety razors from time to time simply because they are great tools.  I could compare them to cartridge razors as well, but safety razors are simply better in every respect.